System and method for transferring playlists

ABSTRACT

A method, computer program product and computing device for selecting at least one playlist for transfer, the at least one playlist being stored on a first personal media device. The at least one playlist is converted to a common format, thus generating a first common format playlist. Communication is established with a second personal media device. The first common format playlist is transferred to the second personal media device.

RELATED APPLICATIONS

This application claims the priority of the following applications,which are herein incorporated by reference: U.S. Provisional ApplicationSer. No. 60/705,764, entitled, “SYSTEMS AND METHODS FOR PRESENTING MEDIACONTENT”, filed 5 Aug. 2005; U.S. Provisional Application Ser. No.60/705,969, entitled, “SYSTEMS AND METHODS FOR USING PERSONAL MEDIADEVICE”, filed 5 Aug. 2005; and U.S. Provisional Application Ser. No.60/705,747, entitled, “PERSONAL MEDIA DEVICE AND METHODS OF USING SAME”,filed 5 Aug. 2005.

TECHNICAL FIELD

This disclosure relates to transferring playlists and, moreparticularly, to transferring playlists between personal media devices.

BACKGROUND

Media distribution systems (e.g., the Rhapsody™ service offered byRealNetworks, Inc of Seattle, Wash.) may distribute media content (e.g.,audio files, video files, and audio/video files) from a media server toa client electronic device (e.g., an MP3 player). A media distributionsystem may distribute media content by allowing a user to download mediadata files and/or receive and process media data streams.

Users of a media distribution system may use playlists to organize themedia content stored on client electronic devices. Unfortunately, asvarious client electronic devices may use different e.g., operatingsystems, memory architectures, and hardware, the playlist from a firstclient electronic device may not be usable on a second client electronicdevice.

SUMMARY OF DISCLOSURE

In a first implementation, a method selects at least one playlist fortransfer, the at least one playlist being stored on a first personalmedia device. The at least one playlist is converted to a common format,thus generating a first common format playlist. Communication isestablished with a second personal media device. The first common formatplaylist is transferred to the second personal media device.

The details of one or more implementations are set forth in theaccompanying drawings and the description below. Other features andadvantages will become apparent from the description, the drawings, andthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a DRM process, a media distributionsystem, a client application, a proxy application, and a personal mediadevice coupled to a distributed computing network;

FIG. 2 is an isometric view of the personal media device of FIG. 1;

FIG. 3 is a diagrammatic view of the personal media device of FIG. 1;

FIG. 4 is a display screen rendered by the client application of FIG. 1;

FIG. 5 is a display screen rendered by the client application of FIG. 1;

FIG. 6 is a display screen rendered by the client application of FIG. 1;

FIG. 7 is a display screen rendered by the client application of FIG. 1;

FIG. 8 is a display screen rendered by the client application of FIG. 1;

FIG. 9 is a display screen rendered by the proxy application of FIG. 1;

FIG. 10 is a display screen rendered by the proxy application of FIG. 1;

FIG. 11 is a display screen rendered by the proxy application of FIG. 1;

FIG. 12 is a diagrammatic view of the media distribution system,personal media device, and distributed computing network of FIG. 1;

FIG. 13 is a diagrammatic view of the media distribution system,personal media device, and distributed computing network of FIG. 1;

FIG. 14 is a diagrammatic view of the two personal media devices coupledto each other with a secure communication channel;

FIG. 15 is a diagrammatic view of an asymmetric key block;

FIG. 16 is a diagrammatic view of a system for subscription baseddigital rights management (DRM) on a personal media device;

FIG. 17 is a flow chart illustrating a method of subscription baseddigital rights management on a personal media device;

FIG. 18 is a diagrammatic view of a system for bulk licensing pre-loadedcontent on a personal media device;

FIG. 19 is a flow chart illustrating a method of bulk licensingpre-loaded content;

FIG. 20 is a flow chart illustrating a method of rendering pre-loadedcontent;

FIG. 21 is a diagrammatic view of a system for queuing media contentitems on a personal media device for future purchase;

FIG. 22 is a flow chart illustrating a method of queuing media contentitems for future purchase;

FIG. 23 is a flow chart illustrating a method of purchasing mediacontent items queued for future purchase;

FIG. 24 is a diagrammatic view of a system for automatically managingmedia content on a personal media device;

FIG. 25 is a flow chart illustrating a method of automatically loadingmedia content;

FIG. 26 is a flow chart illustrating a method of automatically removingmedia content;

FIG. 27 is a diagrammatic view of a system for transferring playlistsbetween personal media devices;

FIG. 28 is a flow chart illustrating a method of transferring playlistsbetween personal media devices;

FIG. 29 is a flow chart illustrating a method of processing playliststransferred between personal media devices;

FIG. 30 is a diagrammatic view of a system for exchanging anddynamically updating user profiles on a personal media device;

FIG. 31 is a flow chart illustrating a method of exchanging userprofiles between personal media devices;

FIG. 32 is a flow chart illustrating a method of dynamically updatinguser profiles;

FIG. 33 is a diagrammatic view of a system for comparing user mediapersonas on a personal media device; and

FIG. 34 is a flow chart illustrating a method of comparing user mediapersonas on a personal media device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

System Overview:

Referring to FIG. 1, there is shown a DRM (i.e., digital rightsmanagement) process 10 that is resident on and executed by personalmedia device 12. As will be discussed below in greater detail, DRMprocess 10 allows a user (e.g., user 14) of personal media device 12 tomanage media content resident on personal media device 12. Personalmedia device 12 typically receives media content 16 from mediadistribution system 18.

As will be discussed below in greater detail, examples of the format ofthe media content 16 received from media distribution system 18 mayinclude: purchased downloads received from media distribution system 18(i.e., media content licensed to e.g., user 14 for use in perpetuity);subscription downloads received from media distribution system 18 (i.e.,media content licensed to e.g., user 14 for use while a validsubscription exists with media distribution system 18); and mediacontent streamed from media distribution system 18, for example.Typically, when media content is streamed from e.g., computer 28 topersonal media device 12, a copy of the media content is not permanentlyretained on personal media device 12. In addition to media distributionsystem 18, media content may be obtained from other sources, examples ofwhich may include but are not limited to files ripped from music compactdiscs.

Examples of the types of media content 16 distributed by mediadistribution system 18 include: audio files (examples of which mayinclude but are not limited to music files, audio news broadcasts, audiosports broadcasts, and audio recordings of books, for example); videofiles (examples of which may include but are not limited to videofootage that does not include sound, for example); audio/video files(examples of which may include but are not limited to a/v newsbroadcasts, a/v sports broadcasts, feature-length movies and movieclips, music videos, and episodes of television shows, for example); andmultimedia content (examples of which may include but are not limited tointeractive presentations and slideshows, for example).

Media distribution system 18 typically provides media data streamsand/or media data files to a plurality of users (e.g., users 14, 20, 22,24, 26). Examples of such a media distribution system 18 include theRhapsody™ service and Rhapsody-To-Go™ service offered by RealNetworks™of Seattle, Wash.

Media distribution system 18 is typically a server application thatresides on and is executed by computer 28 (e.g., a server computer) thatis connected to network 30 (e.g., the Internet). Computer 28 may be aweb server running a network operating system, examples of which mayinclude but are not limited to Microsoft Windows 2000 Server™, NovellNetware™, or Redhat Linux™.

Typically, computer 28 also executes a web server application, examplesof which may include but are not limited to Microsoft IIS™, NovellWebserver™, or Apache Webserver™, that allows for HTTP (i.e., HyperTextTransfer Protocol) access to computer 28 via network 30. Network 30 maybe connected to one or more secondary networks (e.g., network 32), suchas: a local area network; a wide area network; or an intranet, forexample.

The instruction sets and subroutines of media distribution system 18,which are typically stored on a storage device 34 coupled to computer28, are executed by one or more processors (not shown) and one or morememory architectures (not shown) incorporated into computer 28. Storagedevice 34 may include but are not limited to a hard disk drive, a tapedrive, an optical drive, a RAID array, a random access memory (RAM), ora read-only memory (ROM).

Users 14, 20, 22, 24, 26 may access media distribution system 18directly through network 30 or through secondary network 32. Further,computer 28 (i.e., the computer that executes media distribution system18) may be connected to network 30 through secondary network 32, asillustrated with phantom link line 36.

Users 14, 20, 22, 24, 26 may access media distribution system 18 throughvarious client electronic devices, examples of which may include but arenot limited to personal media devices 12, 38, 40, 42, client computer44, personal digital assistants (not shown), cellular telephones (notshown), televisions (not shown), cable boxes (not shown), internetradios (not shown), or dedicated network devices (not shown), forexample.

The various client electronic devices may be directly or indirectlycoupled to network 30 (or network 32). For example, client computer 44is shown directly coupled to network 30 via a hardwired networkconnection. Further, client computer 44 may execute a client application46 (examples of which may include but are not limited to MicrosoftInternet Explorer™, Netscape Navigator™, RealRhapsody™ client,RealPlayer™ client, or a specialized interface) that allows e.g., user22 to access and configure media distribution system 18 via network 30(or network 32). Client computer 44 may run an operating system,examples of which may include but are not limited to MicrosoftWindowst™, or Redhat Linux™.

The instruction sets and subroutines of client application 46, which aretypically stored on a storage device 48 coupled to client computer 44,are executed by one or more processors (not shown) and one or morememory architectures (not shown) incorporated into client computer 44.Storage device 48 may include but are not limited to a hard disk drive,a tape drive, an optical drive, a RAID array, a random access memory(RAM), or a read-only memory (ROM).

As discussed above, the various client electronic devices may beindirectly coupled to network 30 (or network 32). For example, personalmedia device 38 is shown wireless coupled to network 30 via a wirelesscommunication channel 50 established between personal media device 38and wireless access point (i.e., WAP) 52, which is shown directlycoupled to network 30. WAP 52 may be, for example, an IEEE 802.11a,802.11b, 802.11g, Wi-Fi, and/or Bluetooth device that is capable ofestablishing the secure communication channel 50 between personal mediadevice 38 and WAP 52. As is known in the art, all of the IEEE 802.11xspecifications use Ethernet protocol and carrier sense multiple accesswith collision avoidance (i.e., CSMA/CA) for path sharing. The various802.11x specifications may use phase-shift keying (i.e., PSK) modulationor complementary code keying (i.e., CCK) modulation, for example. As isknown in the art, Bluetooth is a telecommunications industryspecification that allows e.g., mobile phones, computers, and personaldigital assistants to be interconnected using a short-range wirelessconnection.

In addition to being wirelessly coupled to network 30 (or network 32),personal media devices may be coupled to network 30 (or network 32) viaa proxy computer (e.g., proxy computer 54 for personal media device 12,proxy computer 56 for personal media device 40, and proxy computer 58for personal media device 42, for example).

Personal Media Device:

For example and referring also to FIG. 2, personal media device 12 maybe connected to proxy computer 54 via a docking cradle 60. Typically,personal media device 12 includes a bus interface (to be discussed belowin greater detail) that couples personal media device 12 to dockingcradle 60. Docking cradle 60 may be coupled (with cable 62) to e.g., auniversal serial bus (i.e., USB) port, a serial port, or an IEEE 1394(i.e., FireWire) port included within proxy computer 54. For example,the bus interface included within personal media device 12 may be a USBinterface, and docking cradle 60 may function as a USB hub (i.e., aplug-and-play interface that allows for “hot” coupling and uncoupling ofpersonal media device 12 and docking cradle 60).

Proxy computer 54 may function as an Internet gateway for personal mediadevice 12. Accordingly, personal media device 12 may use proxy computer54 to access media distribution system 18 via network 30 (and network32) and obtain media content 16. Specifically, upon receiving a requestfor media distribution system 18 from personal media device 12, proxycomputer 54 (acting as an Internet client on behalf of personal mediadevice 12), may request the appropriate web page/service from computer28 (i.e., the computer that executes media distribution system 18). Whenthe requested web page/service is returned to proxy computer 54, proxycomputer 54 relates the returned web page/service to the originalrequest (placed by personal media device 12) and forwards the webpage/service to personal media device 12. Accordingly, proxy computer 54may function as a conduit for coupling personal media device 12 tocomputer 28 and, therefore, media distribution system 18.

Further, personal media device 12 may execute a device application 64(examples of which may include but are not limited to RealRhapsody™client, RealPlayer™ client, or a specialized interface). Personal mediadevice 12 may run an operating system, examples of which may include butare not limited to Microsoft Windows CE™, Redhat Linux™, Palm OS™, or adevice-specific (i.e., custom) operating system.

DRM process 10 is typically a component of device application 64(examples of which may include but are not limited to an embeddedfeature of device application 64, a software plug-in for deviceapplication 64, or a stand-alone application called from within andcontrolled by device application 64). The instruction sets andsubroutines of device application 64 and DRM process 10, which aretypically stored on a storage device 66 coupled to personal media device12, are executed by one or more processors (not shown) and one or morememory architectures (not shown) incorporated into personal media device12. Storage device 66 may be, for example, a hard disk drive, an opticaldrive, a random access memory (RAM), a read-only memory (ROM), a CF(i.e., compact flash) card, an SD (i.e., secure digital) card, aSmartMedia card, a Memory Stick, and a MultiMedia card, for example.

An administrator 68 typically accesses and administers mediadistribution system 18 through a desktop application 70 (examples ofwhich may include but are not limited to Microsoft Internet Explorer™,Netscape Navigator™, or a specialized interface) running on anadministrative computer 72 that is also connected to network 30 (ornetwork 32).

The instruction sets and subroutines of desktop application 70, whichare typically stored on a storage device (not shown) coupled toadministrative computer 72, are executed by one or more processors (notshown) and one or more memory architectures (not shown) incorporatedinto administrative computer 72. The storage device (not shown) coupledto administrative computer 72 may include but are not limited to a harddisk drive, a tape drive, an optical drive, a RAID array, a randomaccess memory (RAM), or a read-only memory (ROM).

Referring also to FIG. 3, a diagrammatic view of personal media device12 is shown. Personal media device 12 typically includes microprocessor150, non-volatile memory (e.g., read-only memory 152), and volatilememory (e.g., random access memory 154); each of which is interconnectedvia one or more data/system buses 156, 158. Personal media device 12 mayalso include an audio subsystem 160 for providing e.g., an analog audiosignal to an audio jack 162 for removable engaging e.g., a headphoneassembly 164, a remote speaker assembly 166, or an ear bud assembly 168,for example. Alternatively, personal media device 12 may be configuredto include one or more internal audio speakers (not shown).

Personal media device 12 may also include a user interface 170 and adisplay subsystem 172. User interface 170 may receive data signals fromvarious input devices included within personal media device 12, examplesof which may include (but are not limited to): rating switches 74, 76;backward skip switch 78; forward skip switch 80; play/pause switch 82;menu switch 84; radio switch 86; and slider assembly 88, for example.Display subsystem 172 may provide display signals to display panel 90included within personal media device 12. Display panel 90 may be anactive matrix liquid crystal display panel, a passive matrix liquidcrystal display panel, or a light emitting diode display panel, forexample.

Audio subsystem 160, user interface 170, and display subsystem 172 mayeach be coupled with microprocessor 150 via one or more data/systembuses 174, 176, 178 (respectively).

During use of personal media device 12, display panel 90 may beconfigured to display e.g., the title and artist of various pieces ofmedia content 92, 94, 96 stored within personal media device 12. Sliderassembly 88 may be used to scroll upward or downward through the list ofmedia content stored within personal media device 12. When the desiredpiece of media content is highlighted (e.g., “Phantom Blues” by “TajMahal”), user 14 may select the media content for rendering usingplay/pause switch 82. User 14 may skip forward to the next piece ofmedia content (e.g., “Happy To Be Just . . . ” by “Robert Johnson”)using forward skip switch 80; or skip backward to the previous piece ofmedia content (e.g., “Big New Orleans . . . ” by “Leroy Brownstone”)using backward skip switch 78. Additionally, user 14 may rate the mediacontent as they listen to it by using rating switches 74, 76.

As discussed above, personal media device 12 may include a bus interface180 for interfacing with e.g., proxy computer 54 via docking cradle 60.Additionally and as discussed above, personal media device 12 may bewireless coupled to network 30 via a wireless communication channel 50established between personal media device 12 and e.g., WAP 52.Accordingly, personal media device 12 may include a wireless interface182 for wirelessly-coupling personal media device 12 to network 30 (ornetwork 32) and/or other personal media devices. Wireless interface 182may be coupled to an antenna assembly 184 for RF communication to e.g.,WAP 52, and/or an IR (i.e., infrared) communication assembly 186 forinfrared communication with e.g., a second personal media device (suchas personal media device 40). Further and as discussed above, personalmedia device 12 may include a storage device 66 for storing theinstruction sets and subroutines of device application 64 and DRMprocess 10. Additionally, storage device 66 may be used to store mediadata files downloaded from media distribution system 18 and totemporarily store media data streams (or portions thereof) streamed frommedia distribution system 18.

Storage device 66, bus interface 180, and wireless interface 182 mayeach be coupled with microprocessor 150 via one or more data/systembuses 188, 190, 192 (respectively).

As discussed above, media distribution system 18 distributes mediacontent to users 14, 20, 22, 24, 26, such that the media contentdistributed may be in the form of media data streams and/or media datafiles.

Accordingly, media distribution system 18 may be configured to onlyallow users to download media data files. For example, user 14 may beallowed to download, from media distribution system 18, media data files(i.e., examples of which may include but are not limited to MP3 files orAAC files), such that copies of the media data file are transferred fromcomputer 28 to personal media device 12 (being stored on storage device66).

Alternatively, media distribution system 18 may be configured to onlyallow users to receive and process media data streams of media datafiles. For example, user 22 may be allowed to receive and process (onclient computer 44) media data streams received from media distributionsystem 18. As discussed above, when media content is streamed from e.g.,computer 28 to client computer 44, a copy of the media data file is notpermanently retained on client computer 44.

Further, media distribution system 18 may be configured to allow usersto receive and process media data streams and download media data files.Examples of such a media distribution system include the Rhapsody™ andRhapsody-to-Go™ services offered by RealNetworks™ of Seattle, Wash.Accordingly, user 14 may be allowed to download media data files andreceive and process media data streams from media distribution system18. Therefore, copies of media data files may be transferred fromcomputer 28 to personal media device 12 (i.e., the received media datafiles being stored on storage device 66); and streams of media datafiles may be received from computer 28 by personal media device 12(i.e., with portions of the received stream temporarily being stored onstorage device 66). Additionally, user 22 may be allowed to downloadmedia data files and receive and process media data streams from mediadistribution system 18. Therefore, copies of media data files may betransferred from computer 28 to client computer 44 (i.e., the receivedmedia data files being stored on storage device 48); and streams ofmedia data files may be received from computer 28 by client computer 44(i.e., with portions of the received streams temporarily being stored onstorage device 48).

Typically, in order for a device to receive and process a media datastream from e.g., computer 28, the device must have an active connectionto computer 28 and, therefore, media distribution system 18.Accordingly, personal media device 38 (i.e., actively connected tocomputer 28 via wireless channel 50), and client computer 44 (i.e.,actively connected to computer 28 via a hardwired network connection)may receive and process media data streams from e.g., computer 28.

As discussed above, proxy computers 54, 56, 58 may function as a conduitfor coupling personal media devices 12, 40, 42 (respectively) tocomputer 28 and, therefore, media distribution system 18. Accordingly,when personal media devices 12, 40, 42 are coupled to proxy computers54, 56, 58 (respectively) via e.g., docking cradle 60, personal mediadevices 12, 40, 42 are actively connected to computer 28 and, therefore,may receive and process media data streams provided by computer 28.

User Interfaces:

As discussed above, media distribution system 18 may be accessed usingvarious types of client electronic devices, which include but are notlimited to personal media devices 12, 38, 40, 42, client computer 44,personal digital assistants (not shown), cellular telephones (notshown), televisions (not shown), cable boxes (not shown), internetradios (not shown), or dedicated network devices (not shown), forexample. Typically, the type of interface used by the user (whenconfiguring media distribution system 18 for a particular clientelectronic device) will vary depending on the type of client electronicdevice to which the media content is being streamed/downloaded.

For example, as the embodiment shown (in FIG. 2) of personal mediadevice 12 does not include a keyboard and the display panel 90 ofpersonal media device 12 is compact, media distribution system 18 may beconfigured for personal media device 12 via proxy application 98executed on proxy computer 54.

The instruction sets and subroutines of proxy application 98, which aretypically stored on a storage device (not shown) coupled to proxycomputer 54, are executed by one or more processors (not shown) and oneor more memory architectures (not shown) incorporated into proxycomputer 54. The storage device (not shown) coupled to proxy computer 54may include but are not limited to a hard disk drive, a tape drive, anoptical drive, a RAID array, a random access memory (RAM), or aread-only memory (ROM).

Additionally and for similar reasons, personal digital assistants (notshown), cellular telephones (not shown), televisions (not shown), cableboxes (not shown), internet radios (not shown), and dedicated networkdevices (not shown) may use proxy application 98 executed on proxycomputer 54 to configure media distribution system 18.

Further, the client electronic device need not be directly connected toproxy computer 54 for media distribution system 18 to be configured viaproxy application 98. For example, assume that the client electronicdevice used to access media distribution system 18 is a cellulartelephone. While cellular telephones are typically not physicallyconnectable to e.g., proxy computer 54, proxy computer 54 may still beused to remotely configure media distribution system 18 for use with thecellular telephone. Accordingly, the configuration information(concerning the cellular telephone) that is entered via e.g., proxycomputer 54 may be retained within media distribution system 18 (oncomputer 28) until the next time that the user accesses mediadistribution system 18 with the cellular telephone. At that time, theconfiguration information saved on media distribution system 18 may bedownloaded to the cellular telephone.

For systems that include keyboards and larger displays (e.g., clientcomputer 44), client application 46 may be used to configure mediadistribution system 18 for use with client computer 44.

Referring also to FIG. 4, when using client application 46 to accessmedia distribution system 18, user 22 may be presented with aninformation display screen 200 rendered by client application 46. Clientapplication 46 typically includes a user interface 202 (e.g., a webbrowser) for interfacing with media distribution system 18 and viewinginformation display screen 200.

When e.g., user 22 streams/downloads media content from e.g., computer28, media distribution system 18 may monitor the media contentstreamed/downloaded to the user's client electronic device (e.g., clientcomputer 44, for example), resulting in the generation of a mediahistory file 100 for that user. While media history file 100 istypically maintained locally (e.g., maintained on client computer 44),media history file 100 may alternatively/additionally be maintainedremotely (e.g., maintained on computer 28) as a remote media historyfile 100′.

The user (e.g., user 22) may save this media history file (or portionsthereof) as a playlist. A playlist is typically a group of tracks(examples of which may include, but are not limited to, songs, videos,news broadcasts, sports broadcasts, etc) that media distribution system18 will render in sequence. This, in turn, allows the user to compilecustom music compilations (in the form of multiple playlists).

A history window 204 may be rendered by client application 46 thatitemizes the information contained within media history file 100. Inthis example, history window 204 itemizes ten (10) media data streams(e.g., “Jailhouse Rock”; “Surf City”; “Runaround Sue”; “The Wanderer”;“The Great Pretender”; “Blueberry Hill”; “I'm Walkin'”; “BlueChristmas”; “Yakety Yak”; and “Peggy Sue”), thus indicating that user 22had previously listened to those ten (10) media data streams.

In addition to media data streams (i.e., media data streams receivedfrom a remote device e.g., computer 28), client application 46 allowsuser 12 to render local media data files. As discussed above, a localmedia data file may be a purchased download received from mediadistribution system 18 (i.e., media content licensed to e.g., user 14for use in perpetuity); a subscription download received from mediadistribution system 18 (i.e., media content licensed to e.g., user 14for use while a valid subscription exists with media distribution system18); and/or a media data file extracted (i.e., ripped) from e.g., amusic compact disc, for example. These local media data files aretypically stored locally on e.g., storage device 48 coupled to clientcomputer 44.

If user 22 wishes to render a local media data file (i.e., a file storedon client computer 44), user 22 may e.g., select the file(s) to berendered using client application 46. Accordingly, user 22 may selectthe dropdown “File” menu 206 using screen pointer 208, which iscontrollable by a pointing device (e.g., a computer mouse, not shown).Selecting the “Open” command may result in client application 46rendering file management window 210, which allows user 22 to selectlocal media data files for playback.

In this example, file management window 210 defines three (3) localmedia data files, namely: “Chantilly Lace” 212; “Great Balls of Fire”214; and “Tutti Frutti” 216, all of which are stored within the folder“My Music”. User 22 may select any (or all) of these files for playbackon client application 46.

A search window 218 allows a user (e.g., user 22) to search for mediacontent. For example, user 22 may enter search terms (e.g., “ElvisPresley”), select the appropriate term type (e.g., artist), and executea query. In the event that multiple artists satisfy the query, a resultset is generated from which user 22 may select e.g., the appropriateartist. Once the appropriate artist is selected, user 22 may review thevarious albums released by the selected artist (or that include tracksby the selected artist). User 22 may then render one or more of thevarious tracks included within any of the albums. Once a track isrendered, identifying information concerning the track rendered is addedto local media history file 100 and/or remote media history file 100′and is included in history window 204. In addition to being able tosearch for media content by artist, user 14 may also be able to searchfor media content by e.g., keyword, track, album and/or composer.

Referring also to FIG. 5 and assuming that user 22 selects all threelocal media data files for playback, media history file 100 is amendedto include three additional entries, namely one for “Chantilly Lace”;one for “Great Balls of Fire”; and one for “Tutti Frutti”. Accordingly,as history window 204 itemizes the information contained within mediahistory file 100, history window 204 will include three additionalentries (i.e., entries 220, 222, 224), which correspond to local mediadata file “Chantilly Lace” 212; local media data file “Great Balls ofFire” 214; and local media data file “Tutti Frutti” 216.

Assuming that user 22 wishes to save this collection of music for futureplayback, user 22 may save the current media history file 100 (or aportion thereof) as a playlist 102 (FIG. 1). While playlist 102 istypically maintained locally (e.g., maintained on client computer 44),playlist 102 may alternatively/additionally be maintained remotely(e.g., maintained on computer 28) as a remote playlist 102′.

Referring also to FIG. 6, user 22 may select the “save” button 240(using screen pointer 208). Once the “save” button 240 is selected, aplaylist naming window 242 is rendered (by client application 46) thatallows user 22 to specify a unique name for playlist 102 within the namefield 244 of playlist naming window 242.

Assuming that user 22 selects “50's Hits” as a playlist name, playlist102 is saved (i.e., as “50's Hits”) and defines the location of all ofthe pieces of media content itemized within history window 204.

Referring also to FIG. 7, once playlist 102 is stored, a link 260 toplaylist 102 (e.g., “50's Hits”) appears in directory window 262. User22 may then select link 260 using screen pointer 208. Once selected, thetracks included within playlist 102 (e.g., “50's Hits”) are itemizedwithin a playlist window 264 (e.g., a web page) viewable via userinterface 202. As discussed above, ten of these entries (namely“Jailhouse Rock”; “Surf City”; “Runaround Sue”; “The Wanderer”; “TheGreat Pretender”; “Blueberry Hill”; “I'm Walkin'”; “Blue Christmas”;“Yakety Yak”; and “Peggy Sue”) define the location of media data streamsand three of these entries (namely “Tutti Frutti”; “Chantilly Lace”; and“Great Balls of Fire”) define the location of media data files.

Typically, playlist window 264 includes hyperlinks that locate (i.e.,provide addresses for) the streams/files associated with the individualentries itemized within playlist 102. This location information isstored within playlist 102. For example, the following table correlatesthe track name of an entry in playlist 102 with an address for thestream/file associated with that track name: Track Name AddressJailhouse www.musicshop.com\songs\jailhouse_rock.ram Rock Surf Citywww.musicshop.com\songs\surf_city.ram Runaroundwww.musicshop.com\songs\runaround_sue.ram Sue The Wandererwww.musicshop.com\songs\the_wanderer.ram The Greatwww.musicshop.com\songs\the_great_pretender.ram Pretender Blueberry Hillwww.musicshop.com\songs\blueberry_hill.ram I'm Walkin'www.musicshop.com\songs\im_walkin.ram Blue Christmaswww.musicshop.com\songs\blue_christmas.ram Yakety Yakwww.musicshop.com\songs\yakety_yak.ram Peggy Suewww.musicshop.com\songs\peggy_sue.ram Tutti Frutti c:\mymusic\tutti_frutti.mp3 Chantilly Lace c:\my music\chantilly_lace.mp3Great Balls c:\my music\great_balls_of_fire.mp3 of Fire

As the first ten entries (namely “Jailhouse Rock”; “Surf City”;“Runaround Sue”; “The Wanderer”; “The Great Pretender”; “BlueberryHill”; “I'm Walkin'”; “Blue Christmas”; “Yakety Yak”; and “Peggy Sue”)identify media data streams, the address provided for each entry pointsto a media stream available from e.g., media distribution system 18.Further, as the last three entries (namely “Tutti Frutti”; “ChantillyLace”; and “Great Balls of Fire”) identify media data files, the addressprovided for each entry points to a media data file available from e.g.,client computer 44.

Playlist window 264 is typically tabular and may include a column 266identifying a media type (i.e., media data stream or media data file,for example) for each entry within playlist window 264. Typically,column 266 includes icons that identify the media type (e.g., icon 268identifies a media data file and icon 270 identifies a media datastream). User 22 may select the “play” button 272 to render playlist102.

As discussed above, media distribution system 18 typically providesmedia data streams and/or media data files to users (e.g., user 22).Typically, metadata is associated with each media data stream providedby media distribution system 18. This metadata may include (but is notlimited to) an artist identifier, an album identifier, a trackidentifier, an album cover image, and a music genre identifier, forexample.

Accordingly, whenever e.g., user 12 renders a remote media data stream,media distribution system 18 may compile and save this metadata (on aper-user basis) to track e.g., listening trends and musical preferencesof individual users, for example.

As discussed above, a local media data file may be a purchased downloadreceived from media distribution system 18 (i.e., media content licensedto e.g., user 14 for use in perpetuity); a subscription downloadreceived from media distribution system 18 (i.e., media content licensedto e.g., user 14 for use while a valid subscription exists with mediadistribution system 18); and/or a media data file extracted (i.e.,ripped) from e.g., a music compact disc, for example.

If the purchased download and/or the subscription download were providedby media distribution system 18, these local media data files wouldtypically also include the metadata described above. Accordingly, whenthese purchased/subscription downloads are rendered by e.g., user 22,the metadata concerning these purchased/subscription downloads may betransmitted from computer 44 to computer 28, such that the metadata iscompiled and saved (on a per user basis) to track e.g., listening trendsand musical preferences, for example.

However, for media data files that were e.g., extracted from musiccompact discs, these data files may not include the above-describedmetadata. As discussed above, media data files (i.e., files stored onclient computer 44) may be rendered using client application 46 andadded to playlists (e.g., playlist 102). Accordingly, whenever user 22attempts to add a media data file (that does not include metadata) to aplaylist (e.g., playlist 102), user 22 may be prompted to providemetadata concerning that media data file.

Referring also to FIG. 8 and continuing with the above-stated example,if user 22 attempts to save a playlist (e.g., playlist 102) thatincludes three local media data files (namely “Tutti Frutti”; “ChantillyLace”; and “Great Balls of Fire”), assuming that these three local mediadata files do not include metadata, client application 46 may render ametadata entry form 280 that allows user 22 to enter metadata concerningeach of the three media data files.

In this example, metadata entry form 280 includes five user-editablefields, namely an artist field 282, an album field 284, a track field286, an album cover image field 288, and a music genre field 290. Albumcover image field 288 may allow user 22 to define a drive, a path, and afilename for an album cover image. Music genre field 290 may be adrop-down menu (operable via screen pointer 208) that allows user 22 toselect a music genre from a number of predefined music genres (notshown).

Typically, if the title of the media data file is descriptive of thetrack name, the track field 286 may be automatically-populated with whatclient application 46 suspects is the track title. As the first localmedia data file is named “tutti frutti”, track field 286 would typicallybe populated with the suspected name “tutti frutti”. User 22 maypopulate the remaining fields and select the save button 292 (usingscreen pointer 208) or alternatively select the cancel button 294.

In order to further automate the metadata generation process, clientapplication 44 may interface with a remote metadata database (not shown)served by e.g., media distribution system 18 or a third party (notshown). This metadata database may define metadata for various tracksand albums. An example of such a database is the CDDB™ databasemaintained by Gracenote™ of Emeryville, Calif. (www.gracenote.com). Forexample, if user 22 ripped each track from an entire compact disc, themetadata database may be accessed by client application 44 and a querymay be structured that defines e.g., the total number of tracks includedon the compact disc, the length of each track included on the compactdisc, and the total length of the compact disc. Assuming that adefinitive result is produced by this query, the metadata for each trackripped from the compact disc would be produced. In the event that anindefinite result set (i.e., one that identifies multiple possiblecompact discs) is generated, user 22 may be prompted to select theappropriate compact disc from a list of possible matches (not shown).

As discussed above, the type of interface used by the user (whenconfiguring media distribution system 18 for a client electronic device)may vary depending on the type and the capabilities of the clientelectronic device to which the media content is beingstreamed/downloaded. Accordingly and as discussed above, mediadistribution system 18 may be configured for personal media device 12via proxy application 98 executed on proxy computer 54.

Proxy application 98 may be automatically executed upon personal mediadevice 12 being placed into docking cradle 60 by e.g., user 14.Alternatively, proxy application 98 may be fully or partially loadedupon boot up of proxy computer 54. Proxy application 98 may then operatein the background until personal media device 12 is placed into dockingcradle 60, at which time proxy application 98 may be fully loaded and/ormoved to the foreground for execution. Further, proxy application 98 maybe manually executed by user 14. As will be discussed below in greaterdetail, proxy application 98 (once executed) may be used to e.g.,configure personal media device 12 and transfer media data files to andremove media data files from personal media device 12, for example.

Referring also to FIG. 9, when using proxy application 98 to accessmedia distribution system 18, user 14 may be presented with ainformation display screen 300 rendered by proxy application 98. Proxyapplication 98 typically includes a user interface 302 (e.g., a webbrowser) for interfacing with media distribution system 18 and viewinginformation display screen 300.

A search window 304 allows a user (e.g., user 14) to search for mediacontent. For example, user 14 may enter search terms (e.g., “ElvisPresley”) into search field 306, select the appropriate term type (e.g.,artist), and execute a query. In the event that multiple artists satisfythe query, a result set is generated from which user 14 may select e.g.,the appropriate artist. Once the appropriate artist is selected, user 14may review the various albums released by the selected artist (or thatinclude tracks by the selected artist). User 14 may then download (foruse on personal media device 12) one or more of the various tracksincluded within any of the albums. In addition to being able to searchfor media content by artist, user 14 may also be able to search formedia content by e.g., keyword, track, album and/or composer.

Additionally, in a fashion similar to that of client application 46,proxy application 98 may be configured to allow user 12 to render (viaproxy computer 54) one or more of the various tracks included within anyof the albums of the selected artist.

A content window 308 may be rendered by proxy application 98 that allowsuser 14 to review the contents of personal media device 12. As discussedabove, personal media device 12 is coupled to proxy computer 54 viae.g., a USB port, serial port, or FireWire port. Upon or duringexecution of proxy application 98, proxy application 98 may pollpersonal media device 12 to retrieve information concerning the mediacontent currently on device 12. This polling may occur in a fashionsimilar to the manner in which the content of a USB hard drive isdetermined. In this particular example, content window 308 includes ten(10) entries, namely: “Jailhouse Rock”; “Surf City”; “Runaround Sue”;“The Wanderer”; “The Great Pretender”; “Blueberry Hill”; “I'm Walkin'”;“Blue Christmas”; “Yakety Yak”; and “Peggy Sue”, thus indicating thatten (10) media data files had been previously downloaded to personalmedia device 12, which are typically stored on storage device 66 ofpersonal media device 12.

Content window 308 may be tabular and itemize various pieces ofinformation concerning the downloaded files, including the track 310,the artist 312, the track length 314 and the track size 316.Additionally, proxy application 98 may poll personal media device 14 toretrieve device identification information, which is rendered within adevice type field 320 and a device serial number field 322 includedwithin content window 308. Further, content window 308 may include asummary information field 324 concerning the current capacity of device12, including one or more of e.g., “Unused Space” in gigabytes; “UsedSpace” in gigabytes; “Unused Space” in percentage of total capacity; and“Used Space” in percentage of total capacity, for example.

Referring also to FIG. 10 and continuing with the above-stated example,assume that user 14 enters the search term “Elvis Presley” into searchfield 306 of search window 304, selects the term type “artist” viadropdown menu 340, and executes the query by selecting the “Go” button342 with screen pointer 208.

Assuming that no other artist satisfies the query, information screen300 may be presented to user 14 with information concerning ElvisPresley, which may include: an artist information screen 344, a toptrack list 346, an album list 348, and a similar artist list 350, forexample.

User 14 may download media data files from media distribution system 18for use on personal media device 12 by selecting the download button 352corresponding to the track to be downloaded. Additionally, user 14 maydownload groups of tracks (e.g., each track included within top tracklist 346, or all tracks included within an single album) by selectingthe download all button 354 corresponding to the tracks to bedownloaded.

Once user 14 selects a track for downloading, proxy application 98 mayrender a download window 356 that e.g., includes a track title field 358that identifies the title of the track being downloaded and an artistfield 360 that identifies the artist of the track being downloaded.

As discussed above, files may be downloaded from media distributionsystem 18 as purchased downloads (i.e., media content licensed to e.g.,user 14 for use in perpetuity), or subscription downloads (i.e., mediacontent licensed to e.g., user 14 for use while a valid subscriptionexists with media distribution system 18). Provided user 14 has acurrent subscription with media distribution system 18, there istypically no additional fee charged for each subscription download, asthe downloaded media content is only renderable while the user has avalid subscription. However, a user typically must pay a fee (e.g., 79¢,89¢, or 99¢, for example) for each purchased download, as the mediacontent is renderable regardless of the status of the user'ssubscription.

Accordingly, download window 356 may include a purchase button 362 and adownload button 364, both of which are selectable via screen pointer208. In this example, if user 14 selects purchase button 362 with screenpointer 208, a media data file for “Hound Dog” by “Elvis Presley” willbe transferred from computer 28 to personal media device 12. Typically,user 14 will be charged e.g., a one-time download fee for downloadingthis media data file. However, as this is a purchased download, themedia data file received is renderable regardless of the status of theuser's subscription with media distribution system 18.

Alternatively, if user 14 selects download button 364 with screenpointer 208, a media data file for “Hound Dog” by “Elvis Presley” willbe transferred from computer 28 to personal media device 12. Typically,user 14 will not be charged a fee for downloading this media data file.However, as this is a subscription download, the media data filereceived is only renderable while user 14 has a valid subscription withmedia distribution system 18.

Download window 356 typically also includes a cancel button 366 forallowing user 14 to cancel the download and close download window 356.

If user 14 selects either purchase button 362 or download button 364,the download of the selected media data file will be initiated. Downloadwindow 356 may include a download status indicator 368 for indicatingthe progress of the download of e.g., “Hound Dog” by “Elvis Presley”.

Referring also to FIG. 11, once the download of the media data file for“Hound Dog” by “Elvis Presley” is completed, content window 308 will beupdated to include an entry 380 for “Hound Dog” by “Elvis Presley”,indicating that “Hound Dog” by “Elvis Presley” was successfullydownloaded from media distribution system 18 to personal media device12.

In a fashion similar to that described above concerning clientapplication 46, user 14 may use proxy application 98 to define playlistsconcerning various media data files stored on personal media device 12.For example, assume that user 14 wished to save the first thirteentracks (namely “Jailhouse Rock”; “Surf City”; “Runaround Sue”; “TheWanderer”; “The Great Pretender”; “Blueberry Hill”; “I'm Walkin'”; “BlueChristmas”; “Yakety Yak”; “Peggy Sue”; “Tutti Frutti”; “Chantilly Lace”;and “Great Balls of Fire”) as a playlist, user 14 would highlight thedesired selection of tracks (using screen pointer 208) and select thesave button 382 using screen pointer 208. A playlist naming window 384may be rendered (by proxy application 98) that allows user 14 to specifya unique name for the playlist within the name field 386 of playlistnaming window 384.

Assuming that user 14 selects “50's Hits” as a playlist name, playlist104 (FIG. 1) named “50's Hits” is defined that locates (within personalmedia device 12) all of the pieces of media content itemized withinplaylist 104. Once playlist 104 is stored, a link 388 to playlist 104(e.g., “50's Hits”) appears in directory window 390. User 14 may thenselect link 388 using screen pointer 208.

Once selected, the tracks included within playlist 104 (e.g., “50'sHits”) are typically itemized within a playlist window 392 (e.g., a webpage) viewable via user interface 302.

As with the playlists described above as being generated using clientapplication 44, playlists generated using proxy application 98 aretypically maintained locally (e.g., maintained on personal media device12). However and as discussed above, playlists mayalternatively/additionally be maintained remotely (e.g., maintained oncomputer 28) as remote playlist 104′.

Device Initialization:

Media distribution system 18 is typically a subscription-based service,in that e.g., user 14 subscribes to media distribution system 18 andpays e.g., a monthly subscription fee to be granted access to mediadistribution system 18. Once user 14 subscribes to media distributionsystem 18, user 14 may obtain media content (for use with personal mediadevice 12) in the form of: purchased downloads received from mediadistribution system 18 (i.e., media content licensed to e.g., user 14for use in perpetuity); subscription downloads received from mediadistribution system 18 (i.e., media content licensed to e.g., user 14for use while a valid subscription exists with media distribution system18); and media content streamed from media distribution system 18, forexample. Typically, when accessing media distribution system 18, user 14must provide user “credentials” that identify the user (e.g., user 14)and/or the device (e.g., device 12) to media distribution system 18.Upon receiving these credentials, media distribution system 18 mayattempt to verify the credentials and, if verified, grant user 14 and/ordevice 12 access to media subscription system 18. The credentialsreceived and verified by media distribution system 18 may include, butare not limited to, a user name, a user password, a user key, a devicename, a device password, a device key, and/or one or more digitalcertificates.

Typically, upon personal media device 12 being placed into dockingcradle 60, personal media device 12 establishes a connection with mediadistribution system 18 via proxy computer 54. As discussed above, proxycomputer 54 may function as an Internet gateway for personal mediadevice 12 and, therefore, allow personal media device 12 to accesscomputer 28 and media distribution system 18.

Once a connection is establish with media distribution system 18, DRMprocess 10 may be initiated. DRM process 10 is typically executed at thetime personal media device 12 is initially configured (i.e., the firsttime personal media device 12 establishes a connection with mediadistribution system 18). As will be discussed below in greater detail,DRM process 10 may be systematically and repeatedly executed to verifythat device 12 (and/or user 14) are active subscribers of mediadistribution system 18.

Referring also to FIG. 12, at the time of manufacture, personal mediadevice 12 may include a private encryption key (e.g., device private key400) and a public encryption key (e.g., device public key 402) stored innon-volatile memory (e.g., ROM 152 and/or storage device 66). Keys 400,402 may be 1024-bit asymmetric encryption keys and may be referred to asDRM (i.e., digital rights management) keys.

As is known in the art, a private key/public key encryption methodologyallows users of an unsecure network (e.g., the Internet) to securelyexchange data through the use of a pair of encryption keys, namely theprivate encryption key (e.g., device private key 400) and the publicencryption key (e.g., device public key 402). The private key/public keyencryption methodology is typically referred to as an asymmetricencryption methodology, in that the key used to encrypt a message isdifferent than the key used to decrypt the message.

In private key/public key encryption, the private encryption key (e.g.,device private key 400) and the public encryption key (e.g., devicepublic key 402) are typically created simultaneously using the samealgorithm (e.g., the RSA algorithm created by Ron Rivest, Adi Shamir,and Leonard Adlemana, for example). Device private key 400 is typicallygiven only to the requesting party and device public key 402 istypically made publicly available (e.g., as part of digital certificate404). Typically, device private key 400 is not shared and is maintainedsecurely within e.g., personal media device 12.

Accordingly, when a secure message is to be sent from a sender to arecipient, the public key (e.g., device public key 402) of the recipient(which is readily accessible to the sender) is used to encrypt themessage. Once encrypted, the message is sent to the recipient and canonly be decrypted using the recipient's private key (e.g., deviceprivate key 400). As private key 400 is maintained securely by therecipient, only the recipient can decrypt the encrypted message.

In addition to encrypting and decrypting messages, a sender mayauthenticate their identity by using their private key (e.g., deviceprivate key 400) to encrypt a digital certificate, which is then sent toa recipient (i.e., the person to which they are authenticating theiridentity). Accordingly, when the digital certificate is received by therecipient, the recipient can decrypt the encrypted digital certificateusing the sender's public key (e.g., device public key 402), thusverifying that the digital certificate was encrypted using the sender'sprivate key (e.g., device private key 400) and, therefore, verifying theidentity of the sender.

DRM process 10 may generate a challenge 406, which is typically a randomnumber generated by a random number generation process (not shown)included within personal media device 12. Once generated, challenge 406is paired with device digital certificate 404 (which typically includesdevice public key 402), to form a license request 408. Device digitalcertificate 404, which may be referred to as a DRM digital certificate,may include additional information such as a device serial number (e.g.,137660523-1 from device serial number field 322, FIG. 9), for example.

As discussed above, proxy application 98 allows the owner of device 12(e.g., user 14) to: configure device 12 for use with media distributionsystem 18; and configure media distribution system 18 for use withdevice 12. Typically, when proxy application 98 is configured on proxycomputer 54, user 14 may be required to provide user credentials thatidentify the user (e.g., user 14) and define a valid subscription thatwould allow user 14, device 12, and proxy application 98 to access mediadistribution system 18. Alternatively or additionally, personal mediadevice 12 may be configured to allow the user (e.g., user 14) todirectly enter the user credentials (via device 12) when device 12 isinitially configured.

DRM process 10 may provide license request 408 (via network 30 and/ornetwork 32) to media distribution system 18. Additionally, if definedwithin personal media device 12, a user ID 410 (e.g., enumerating theuser credentials described above) may also be included within licenserequest 408. As discussed above, the user credentials (i.e., includedwithin user ID 410) may include, but are not limited to, a user name, auser password, a user key, a device name, a device password, a devicekey, and/or one or more digital certificates. Prior to being provided tomedia distribution system 18, DRM process 10 may digitally sign licenserequest 408 using device private key 400.

A digital signature is an electronic signature that uses the privatekey/public key encryption methodology (described above) and allows asender of a message to authenticate their identity and the integrity ofmessage sent. A digital signature may be used with both encrypted andnon-encrypted messages and does not impede the ability of the receiverof the message to read the message.

For example, assume that DRM process 10 digitally signed license request408 prior to providing license request 408 to media distribution system18. When digitally signing license request 408, a mathematical functionis typically performed on the content of license request 408. Forexample, a message hash of license request 408 may be calculated bypersonal media device 12, such that a message hash is the mathematicaloutput of a known one-way hash function that transforms a string ofcharacters (e.g., license request 408) into a usually shorterfixed-length value that represents the original string of characters. Asthe hashing function is a one-way mathematical function, once a messagehash is generated, the original message cannot be retrieved byprocessing the message hash. DRM process 10 may then encrypt the messagehash (using device private key 400) to create the digital signature (notshown). This digital signature may then be attached to license request408. Accordingly, while the digital signature is encrypted, the originalmessage (i.e., license request 408) need not be. Therefore, licenserequest 408 may be processed by media distribution system 18 even if thedigital signature is not processed.

Continuing with the above-stated example, license request 408 and thedigital signature may be received by media distribution system 18, andmedia distribution system 18 may use the same hash function to generatea message hash of license request 408. Media distribution 408 will alsodecrypt the digital signature received from personal media device 12using device public key 402 (included within device digital certificate404) to recreate the message hash calculated by personal media device12. Media distribution system 18 may then compare the decrypted digitalsignature to the message hash calculated by the media distributionsystem 18. If the message hashes match, the integrity of license request408 and the identity of personal media device 12 are both validated.

Additionally, the integrity of device digital certificate 404 (and,therefore, device public key 402) may be verified when license request408 is received from personal media device 12. Digital certificates aretypically issued and digitally signed by e.g., certification authority412 using CA private key 414. Accordingly, device digital certificate404 may be verified by obtaining the CA public key 416 to verify thedigital signature of device digital certificate 404.

Once challenge 406, device digital certificate 404, and user ID 410(i.e., license request 408) are received by media distribution system18, media distribution system 18 may access data store 418 to retrievesubscription information concerning user 14 (i.e., the user definedwithin user ID 410) and determine e.g., the date at which the currentsubscription of user 14 will expire. Data store 418 may be maintained onstorage device 34 coupled to computer 28.

Assume, for illustrative purposes, that media distribution system 18 isconfigured to automatically bill each subscriber on the first of eachmonth for the subscription fee for the upcoming month. Accordingly, on01 Mar. 2005, user 14 will be billed for the cost of their March 2005subscription. Therefore, if media distribution system 18 retrievessubscription information concerning user 14 on 6 Mar. 2005, thesubscription information retrieved will indicate that user 14 has avalid subscription until 31 Mar. 2005.

Accordingly and continuing with the above-stated example, when licenserequest 408 is received, media distribution system 18 may retrievesubscription information concerning user 14. In this example, thesubscription information will indicate that user 14 is a validsubscriber (to media distribution system 18) through 31 Mar. 2005.

Media distribution system 18 may generate a timeout indicator 420, whichindicates e.g., the user's subscription information and the expirationdate of the user's current subscription. In this example, timeoutindicator 420 will indicate e.g., that the subscription of user 14 willexpire on 31 Mar. 2005. Media distribution system 18 may obtain userencryption key 422 (i.e., the encryption key for user 14) from datastore 418. Media distribution system 18 may then encrypt user encryptionkey 422, using device public key 402, to generate encrypted userencryption key 422′ (shown with a hash fill). Timeout indicator 420,challenge 406, device digital certificate 404 (including device publickey 402), user ID 410, and encrypted user encryption key 422′ may becombined (by media distribution system 18) to form device license 424.

Device license 418 may further include a system time indicator 426,which indicates the system time as defined by media distribution system18. System time indicator 426 may be used to synchronize a system clock194 (FIG. 3) included within personal media device 12 with a systemclock 428 included within media distribution system 18.

Device license 424 may further include a licensing service (i.e., LS)digital certificate 430, which typically includes a licensing service(i.e., LS) public key 432.

Media distribution system 18 may digitally sign device license 424 usinglicensing service (i.e., LS) private key 434 (of media distributionsystem 18) and provide device license 424 to personal media device 12.Licensing system private key 434 may be stored on data store 418.

When device license 424 is received from media distribution system 18,DRM process 10 may verify the integrity of LS digital certificate 430(and, therefore, LS public 432). As discussed above, digitalcertificates are typically issued and digitally signed by e.g.,certification authority 412 using CA private key 414. Accordingly, LSdigital certificate 430 may be verified by obtaining the CA public key416 to verify the digital signature of LS digital certificate 430.

DRM process 10 may use LS public key 432 (included within LS digitalcertificate 430) to verify device license 424 (which was digitallysigned using LS private key 434). DRM process 10 may additionally verifychallenge value 406, device public key 402, and the device serial number(included within device digital certificate 404) to ensure that devicelicense 424 is intended for personal media device 12. DRM process 10 maythen decrypt, with device private key 400, encrypted user encryption key422′ (that was encrypted using device public key 402) to generate userencryption key 422 (which may be stored in non-volatile memory, examplesof which include ROM 152 (FIG. 3) and/or storage device 66 (FIG. 3).User ID 410, user encryption key 422, and timeout indicator 420 may besaved on e.g., non-volatile memory, examples of which include ROM 152(FIG. 3) and/or storage device 66 (FIG. 3), for use when personal mediadevice 12 renders media content downloaded from media distributionsystem 18. Additionally, as will discussed below in greater detail, DRMprocess 10 may retain a copy of device license 424 for use whentransferring media content between personal media device 12 and e.g.,personal media device 40.

Obtaining Media Content:

As discussed above, once user 14 subscribes to media distribution system18, user 14 may obtain from media distribution system 18 media content(for use with personal media device 12) in the form of: purchaseddownloads received from media distribution system 18 (i.e., mediacontent licensed to e.g., user 14 for use in perpetuity); subscriptiondownloads received from media distribution system 18 (i.e., mediacontent licensed to e.g., user 14 for use while a valid subscriptionexists with media distribution system 18); and media content streamedfrom media distribution system 18, for example.

Referring also to FIG. 13, each media data file 450, 452, 454, 456, 458downloadable from media distribution system 18 may be encrypted using aunique CEK (i.e., content encryption key) 460, 462, 464, 466, 468respectively. For example, if media distribution system 18 includes1,000,000 media data files available for downloading to e.g., personalmedia device 12, media distribution system 18 will encrypt each mediadata file using a unique encryption key. Accordingly, for 1,000,000media data files, 1,000,000 unique CEK's will be required, each of whichis bound to the media data file to which the CEK is related.Accordingly, CEK 460 is bound to media data file 450, and CEK 462 isbound to media data file 452, for example.

Each CEK (e.g., keys 460, 462, 464, 466, 468) may be a symmetricencryption key, in that the key used to encrypt a media data file mayalso be used to decrypt the same media data file. Additionally, eachmedia data file may be stored on e.g., storage device 34 attached tocomputer 28.

As discussed above, search window 304 (FIG. 10) of proxy application 98,may allow user 14 to search for media data files. Additionally, user 14may download media data files from media distribution system 18 for useon personal media device 12 by selecting the download button 352 (FIG.10) corresponding to the media data file to be downloaded.

Once the download of a media data file is initiated, personal mediadevice 12 may submit the appropriate request(s) to media distributionsystem 18. For example, assume that user 14 wished to download threemedia data files, namely media data files 450, 454, 456. DRM process 10would submit requests 470, 472, 474 respectively, each of which requeststhe desired file. For security and authentication purposes, requests470, 472, 474 may be e.g., encrypted by personal media device 12 (usinge.g., LS public key 432) and/or digitally signed by personal mediadevice 12 (using e.g., device private key 400). Accordingly, if arequest is encrypted (using e.g., LS public key 432), the encryptedrequest may subsequently be decrypted by media distribution system 18using LS private key 434. Further, if a request is digitally signed(using e.g., device private key 400), the signed request maysubsequently be verified by media distribution system 18 using devicepublic key 402.

Once e.g., requests 470, 472, 474 are received and processed by mediadistribution system 18, media distribution system 18 may retrieve therequested media data files 450, 454, 456 from e.g., storage device 34.As discussed above, each media data file is currently encrypted using aunique CEK, such that the CEK is bound to the media data file.

Prior to being downloaded to personal media device 12, each media datafile to be downloaded is bound to the user (e.g., user 14) who requestedthe download. As discussed above, during device initialization, personalmedia device 12 provides license request 408 to media distributionsystem 18. Media distribution system 18 in turn processes license 408and obtains current subscription information concerning the userassociated with license request 408 (e.g., user 14). As discussed above,this initialization process may occur periodically and, therefore, mayoccur at the time that personal media device 12 is placed into dockingcradle 60 (FIG. 2). Accordingly and for this example, assume thatpersonal media device 12 has provided the required user credentials toproperly access media distribution system 18. As discussed above, theuser credentials provided to media distribution system 18 may include,but are not limited to, a user name, a user password, a user key, adevice name, a device password, a device key, and/or one or more digitalcertificates.

Once media distribution system 18 retrieves the requested media datafiles 450, 454, 456 from e.g., storage device 34, media distributionsystem 18 binds the retrieved media distribution files 450, 454, 456 touser 14 e.g., the user requesting the media data files, thus creatingbound media data files 476, 478, 480. Accordingly, the contentencryption key (e.g., CEK 460) associated with each media data file(e.g., media data file 450) is encrypted using the encryption key (e.g.,user encryption key 422) of the user requesting the media data files(e.g., user 14). Accordingly, CEK 460 is encrypted to generate CEK 460′,CEK 464 is encrypted to generate CEK 464′, and CEK 466 is encrypted togenerate CEK 466′. Once encrypted, bound media data files 476, 478, 480(including encrypted CEK's 460′, 464′, 466′ respectively) are providedto personal media device 12. As the CEK of each bound media data files476, 478, 480 is encrypted using e.g., user encryption key 422, boundmedia data files 476, 478, 480 may only be processed (e.g., rendered) bya personal media device in possession of user encryption key 422. Asdiscussed above, a copy of user encryption key 422 is stored onnon-volatile memory within personal media device 12. Once bound mediadata files 476, 478, 480 are received by personal media device, they maybe stored on e.g., storage device 66 within personal media device 12.

Media Content Playback:

As discussed above, user ID 410, user encryption key 422, and timeoutindicator 420 may be saved for use when personal media device 12 rendersmedia content downloaded from media distribution system 18.

Continuing with the above-stated example, if user 14 wishes to renderone of bound media data files 476, 478, 480, user 14 may select theappropriate media data file via the controls (e.g., backward skip switch78; forward skip switch 80; play/pause switch 82; menu switch 84; radioswitch 86; and slider assembly 88, for example) and display panel 90 ofpersonal media device 12. Once one or more media data files are selectedfor playback, the appropriate file(s) are retrieved from e.g., storagedevice 66. As discussed above, prior to each media data file beingprovided to personal media device 12, the CEK of each media data filemay be encrypted (by media distribution system 18) using user encryptionkey 422. As discussed above, user encryption key 422 may be a symmetricencryption key and, therefore, the key used to e.g., encrypt CEK 460 mayalso be used to decrypt encrypted CEK 460′.

Once the appropriate bound media data files are retrieved from e.g.,storage device 66, DRM process 10 may decrypt the appropriate CEK (usinguser encryption key 422) so that the media data file can be processedand rendered on personal media device 12. For example, if user 14 wishedto render bound media data files 476, 478, personal media device 12would decrypt encrypted CEK 460′ to generate CEK 460. CEK 460 may thenbe used by DRM process 10 to decrypt media data file 450 for playback bypersonal media device 12. Further, DRM process 10 would decryptencrypted CEK 464′ to generate CEK 464. CEK 464 may then be used by DRMprocess 10 to decrypt media data file 454 for playback by personal mediadevice 12.

Typically, prior to processing and rendering e.g., bound media datafiles 476, 478, DRM process 10 will verify that e.g., user 14 hassufficient rights to process and render the bound media data files.

As discussed above, media distribution system 18 is typically asubscription-based service, in that e.g., user 14 subscribes to mediadistribution system 18 and pays e.g., a monthly subscription fee to begranted access to media distribution system 18. Further, user 14 mayobtain from media distribution system 18 subscription downloads thatallow user 14 to process and playback the subscription downloads onlywhile a valid subscription exists with media distribution system 18.

Assuming that bound media data files 476, 478, 480 are subscriptiondownloads (as opposed to purchased downloads that are licensed inperpetuity for use by user 14), prior to rendering and/or processingbound media data files 476, 478, 480, DRM process 10 may obtain timeoutindicator 420, which as discussed above may be stored on e.g.,non-volatile memory, examples of which include ROM 152 (FIG. 3) and/orstorage device 66 (FIG. 3). DRM process 10 may then compare theexpiration date (e.g., 31 Mar. 2005) defined within timeout indicator420 to the date and/or time defined within system clock 194 to determineif e.g., user 14 is still allowed to render bound media data files 476,478, 480. In this example, as user 14 has a valid subscription through31 Mar. 2005 and the current date and time (as defined by system clock194) is 17:53 GMT on 6 Mar. 2005, the subscription of user 14 (withrespect to media distribution system 18) is valid and current.Accordingly, bound media data files 476, 478, 480 may be processed forplayback.

Device-to-Device Media Content Transfer:

As discussed above, media distribution system 18 is typically asubscription-based service, in that e.g., user 14 subscribes to mediadistribution system 18 and pays e.g., a monthly subscription fee to begranted access to media distribution system 18. Further, user 14 mayobtain from media distribution system 18 subscription downloads thatallow user 14 to process and playback the subscription downloads onlywhile a valid subscription exists with media distribution system 18.Accordingly, since the rights associated with a subscription downloadare based upon the existence of a valid subscription with mediadistribution system 18, subscription downloads may be transferred from afirst personal media device to a second media device, as long as a validsubscription exists concerning the second personal media device.

Referring also to FIG. 14 and continuing with the above-stated example,assume that user 14 has downloaded bound media data files 476, 478, 480which are stored on e.g., storage device 66 within personal media device12. Further, assume that user 26 wishes to obtain a copy of bound mediadata file 476 for playback on personal media device 40. As discussedabove, when a device is initialized, a copy of a device license istransferred to and retained on the personal media device for use whentransferring media content between personal media devices. Accordingly,personal media device 12 includes source device license 424 and personalmedia device 40 includes target device license 500.

Typically, a device-to-device content transfer is initiated by the userof the source device. In the above-stated example, personal media device12 is the source device and personal media device 40 is the targetdevice. Accordingly, user 14 may initiate the transfer of bound mediadata file 476 from personal media device 12 to personal media device 40.

Referring again to FIG. 2, if e.g., user 14 wishes to transfer a mediadata file to another personal media device, user 14 may depress menuswitch 84, resulting in the generation of e.g., pop-up menu 106. Usingslider assembly 88, user 14 may select the “Share Content” command 108from pop-up menu 106, resulting in the generation of content window 110.From content window 110, user 14 may select the appropriate file fortransfer. Assume that user 14 selects “Peggy Sue”, which corresponds tobound media data file 476. Once user 14 selects the track for transfer,device application 64 may render a transfer window 112 that e.g.,includes a track title field 114 that identifies the title of the trackbeing transferred and an artist field 116 that identifies the artist ofthe track being transferred.

Transfer window 112 may include a transfer button 118 (selectable viaslider assembly 88) for initiating the transfer of bound media data file476 to e.g., personal media device 40. In this example, if user 14selects transfer button 118 with slider assembly 88, the transfer ofbound media data file 476 (i.e., “Peggy Sue” from “Buddy Holly”) frompersonal media device 12 to (in this example) personal media device 40is initiated. Transfer window 112 may include a transfer statusindicator 120 for indicating the progress of the transfer of e.g.,“Peggy Sue” by “Buddy Holly”. Transfer window 112 may further include acancel button 122 for allowing user 14 to cancel the file transfer andclose download window 112.

Referring again to FIG. 14, once the transfer of bound media data file476 is initiated, the devices may exchange device digital certificatesfor authentication purposes. For example, DRM process 10 may providesource device digital certificate 404 (which includes source devicepublic key 402) to device personal media device 40 for authentication.As discussed above, the integrity of source device digital certificate404 (and, therefore, source device public key 402) may be verified (bypersonal media device 40) via CA public key 416 (a copy of which istypically stored in non-volatile memory 502 of personal media device40), as source device digital certificate 404 was issued and digitallysigned by e.g., certification authority 412 (FIG. 12) using CA privatekey 414 (FIG. 12).

Further, personal media device 40 may provide target device digitalcertificate 504 (which includes target device public key 506) to devicepersonal media device 12 for authentication. The integrity of targetdevice digital certificate 504 (and, therefore, target device public key506) may be verified by DRM process 10 via CA public key 416 (a copy ofwhich is typically stored in non-volatile memory 66/152 of personalmedia device 12), as target device digital certificate 504 wouldtypically also have been issued and digitally signed by e.g.,certification authority 412 (FIG. 12) using CA private key 414 (FIG.12).

As discussed above and as illustrated in FIG. 3, personal media devices(e.g., personal media device 12) may include a wireless interface 182for wirelessly-coupling personal media device 12 to network 30 (ornetwork 32) and/or other personal media devices. Wireless interface 182may be coupled to an antenna assembly 184 for RF communication to e.g.,WAP 52, and/or an IR (i.e., infrared) communication assembly 186 forinfrared communication with e.g., a second personal media device (suchas personal media device 40). Accordingly, communication betweenpersonal media devices 12, 40 may occur wirelessly via RF communicationand/or infrared communication. Additionally, an external connector (notshown) may be included within each personal media device that allows forthe hardwired-interconnection of multiple personal media devices.

Once certificates 404 and 504 are verified, personal media device 40provides target device license 500 to personal media device 12. As withdevice license 424 (FIG. 11), target device license 500 may include: LSdigital certificate 508 (which includes LS public key 432), system timeindicator 512, timeout indicator 514 (i.e., for the subscription of user26), encrypted user encryption key 516 (i.e., for user 26), user ID 518(i.e., for user 26), challenge 520, and target device digitalcertificate 502 (which includes a copy of target device public key 504).

Upon receiving target device license 500 from personal media device 40,DRM process 10 may verify the integrity of target device license 500.Accordingly, DRM process 10 may verify the integrity of LS digitalcertificate 508 (and, therefore, LS public key 432). As discussed above,digital certificates are typically issued and digitally signed by e.g.,certification authority 412 (FIG. 12) using CA private key 414 (FIG.12). Accordingly, LS digital certificate 508 may be verified by DRMprocess 10 using CA public key 416.

DRM process 10 may use LS public key 432 (included within LS digitalcertificate 508) to verify target device license 500 (which wasdigitally signed using LS private key 434 (FIG. 12)). DRM process 10 mayadditionally verify that user 26 has a valid subscription to mediadistribution system 18 by comparing timeout indicator 514 to systemclock 194. For example, as user 26 has a valid subscription through 22Mar. 2005 (as defined by timeout indicator 514) and the current date andtime (as defined by system clock 194) is 22:06 GMT on 13 Mar. 2005, thesubscription of user 26 (with respect to media distribution system 18)is valid and current.

Assuming that the integrity of target device license 500 is verified,the transfer of bound media data file 476 may begin. Depending on themanner in which DRM process 10 is configured, user 26 may be required tohave a valid and current subscription (with media distribution system18) prior to initiating the transfer of any media data files to personalmedia device 40. However and as discussed above, since the personalmedia device checks for the existence of a valid and currentsubscription prior to rendering media data files, even is the transferwas effectuated while user 26 did not have a valid and currentsubscription with media distribution system 18, user 26 would beprohibited from rendering the transferred media data files.

In order to effectuate the media data file transfer, DRM process 10generates a random session key (i.e., RSK) 522, which is encrypted usingtarget device public key 504 (included within target device digitalcertificate 504) to generate encrypted RSK 522′. DRM process 10 providesencrypted RSK 522′ to personal media device 40, which is decrypted(using target device private key (not shown)) to retrieve RSK 522. RSK522 may be a 1024-bit symmetric encryption key.

As personal media device 12 and personal media device 40 each contain acopy of RSK 522, a secure communication channel 524 may be establishedbetween devices 12, 40, in which all data transmitted across securecommunication channel 524 is encrypted (using RSK 522) prior totransmission and decrypted (using RSK 522) upon receipt. Securecommunication channel 524 may be a wireless communication channel (usinge.g., RF communication and/or infrared communication), or a wiredcommunication channel (using an external connector (not shown) ondevices 12, 40).

DRM process 10 may retrieve (from e.g., storage device 66) bound mediadata file 476 for transmission to personal media device 40. However andas discussed above, as CEK 460′ of bound media data file 476 wasencrypted using the encryption key of user 12 (e.g., user encryption key422), bound media data file 476 will not be accessible (in its currentform) by user 26. Therefore, bound media data file 476 must be unboundfrom user 12 and bound to user 26. Accordingly, DRM process 10 obtainsbound media data file 476 from e.g., storage device 66 and decrypts CEK460′ (using user encryption key 422) to obtain CEK 460. Unbound mediadata file 526 may be transferred (via secure communication channel 524)from personal media device 12 to personal media 40. Upon receipt,personal media device 40 may encrypt CEK 460 of unbound media data file526, using the encryption key of user 26 (i.e., user encryption key 528)to generate bound media data file 530, which includes encrypted CEK460″. Personal media device 40 may store bound media data file 530 forsubsequent rendering in non-volatile memory 502.

User encryption key 422 is described above as typically being asymmetric encryption key, in that the same key that is used to encrypt aCEK may also be used to decrypt the encrypted version of the CEK.Further and as described above, the same user encryption key 422 is usedto encrypt all CEK's. Therefore, if one-hundred bound media data filesare downloaded to and stored upon personal media device 12, the sameuser encryption key 422 may be used to decrypt each of the one-hundredencrypted CEKs. However, other configurations of user encryption key 422are possible.

For example, user encryption key 422 may be a symmetric key block, asopposed to a single symmetric key. Referring also to FIG. 15, there isshown a 32-byte (i.e., 256-bit) symmetric key block 600. Assume for thisexample that a 16-byte (i.e., 128-bit) key is used to encrypt anddecrypt each encrypted CEK. Through the use of one e.g., 256-bitsymmetric key block 600, multiple 128-bit symmetric keys (e.g., userencryption keys 602, 604, 606, 608 may be defined. For example, a firstuser encryption key 602 may be defined as bits 000-127 of symmetric keyblock 600. A second user encryption key 604 may be defined as bits004-131 of symmetric key block 600. A third user encryption key 606 maybe defined as bits 128-255 of symmetric key block 600. And a fourth userencryption key 608 may be defined as bits 124-251 of symmetric key block600. Accordingly, a plurality of unique symmetric user encryption keysmay be defined using a single symmetric key block 600. Accordingly, toproperly define the individual user encryption keys, in this particularexample, a bit shift parameter 610 is defined for each user encryptionkey 602, 604, 606, 608, which defines the starting point of therespective key. For example, user encryption key 602 starts at bit-0 ofsymmetric key block 600 and, therefore, has a bit shift 610 of 0-bits.As user encryption key 604 starts at bit-4 of symmetric key block 600,user encryption key 604 has a bit shift 610 of 4-bits. As userencryption key 606 starts at bit-128 of symmetric key block 600, userencryption key 606 has a bit shift 610 of 128-bits. As user encryptionkey 608 starts at bit-124 of symmetric key block 600, user encryptionkey 608 has a bit shift 610 of 124-bits.

While various user encryption keys are defined within symmetric keyblock 600 by shifting the starting point of each individual userencryption key, other configurations are possible. For example, keys maybe defined using only odd or even bits in conjunction with a bit shift.Additionally and/or alternatively, keys may be defined within symmetrickey block 600 algorithmically, in that an algorithm is used to definethe individual bits used (within symmetric key block 600) to define aunique user encryption key.

Various systems and methods of using a personal media device aredescribed below. Each of these systems and methods may be implemented ona personal media device 12 and in connection with a media distributionsystem 18, for example, as described above. The systems and methods maybe implemented using one or more processes executed by personal mediadevice 12, proxy computer 54 and/or server computer 28, for example, inthe form of software, hardware, firmware or a combination thereof. Eachof these systems and methods may be implemented independently of theother systems and methods described herein. As described above, personalmedia device 12 may include a dedicated personal media device (e.g., anMP3 player), a personal digital assistant (PDA), a cellular telephone,or other portable electronic device capable of rendering digital mediadata.

Subscription-Based Digital Rights Management:

Referring to FIGS. 16 and 17, there is shown a system and method forproviding subscription-based digital rights management (DRM) on personalmedia device 12. According to subscription-based DRM, personal mediadevice 12 is licensed or registered to a user and content rightsassociated with licensed media content 1102 are bound to the user ofpersonal media device 12 under a subscription to a media distributionsystem 18. Thus, a user is able to obtain and/or render licensed mediacontent 1102 on personal media device 12 provided that personal mediadevice 12 maintains a valid license under a user subscription.

Licensed media content 1102 may be provided as one or more media datafiles pre-loaded on, downloaded to, or transferred to personal mediadevice 12. As described above, licensed media content 1102 may includemedia data files such as audio files (e.g., music), video files,audio/video files, and multimedia content. Licensed media content 1102may be arranged and presented as individual media content items (e.g.,musical tracks) that may be individually and selectively rendered (e.g.,subscription content or purchased content) or as multiple content items(e.g., a series of musical tracks) that may only be played in a definedsequence in compliance with performance complement requirements and withlimited or no user interaction (e.g., non-interactive content).

Media content 1102 licensed by media distribution system 18 may havedifferent content rights associated with different media data files.Content rights may include, for example: non-subscription rights (e.g.,purchased content rights) that allow content to be rendered and/orcopied (e.g., burned to CD) by the licensed user indefinitelyindependent of a valid subscription; and subscription-based rights thatallow content to be streamed, downloaded, rendered and/or transferred bythe licensed user for a limited period of time under a validsubscription. Content rights associated with a particular media datafile may be defined in a content license associated with the media datafile (e.g., embedded in the media data file or in a separate contentlicense database).

To protect licensed media content 1102, media data files may beencrypted with associated content encryption keys 1104. To bind thelicensed content 1102 to a user, content encryption keys 1104 may beencrypted with user encryption key 422, for example, as described above.User encryption key 422 may be included in device license 424 with other“user credentials” such as user ID 410 and expiration data 420 (e.g., atimeout indicator) used to verify the user's subscription.

DRM process 1110 may be resident on and executed by personal mediadevice 12 to perform the core functions and/or processes associated withdigital rights management (e.g., as described above). Content playbackengine 1120 may be resident on and executed by personal media device 12to perform the core functions and/or processes associated with renderingmedia content such as processing media data files. Although contentplayback engine 1120 and DRM process 1110 are shown as separatefunctional components, DRM process 1110 may be incorporated withincontent playback engine 1120. DRM process 1110 and content playbackengine 1120 may be components of device application 64 (FIG. 1), forexample, as an embedded feature, software plug-in, or stand-aloneapplication. The instruction sets and subroutines of DRM process 1110and content playback engine 1120 may be executed by one or moreprocessors (not shown) and one or more memory architectures (not shown)incorporated into personal media device 12.

An exemplary method of subscription-based DRM is illustrated in FIG. 17and is described below. A user may be registered 1150 with mediadistribution system 18 to obtain a subscription to the mediadistribution system, for example, during the device initializationprocess (as described above). The user may also register 1150 to obtainthe subscription before the device initialization process. Personalmedia device 12 may be registered 1152 with media distribution system 18under the user subscription, for example, during the deviceinitialization process (as described above). DRM process 1110 onpersonal media device 12, for example, may perform the core functionsand/or processes associated with the user registration and/or deviceregistration during device initialization. As a result of a userregistration 1150 and device registration 1152, device license 424 maybe generated and stored on personal media device 12.

During use, personal media device 12 may receive 1154 a request by theuser to obtain and/or render licensed media content 1102 licensed bymedia distribution system 18. Upon receiving a request to obtain and/orrender a content item, personal media device 12 may determine 1160 e.g.,if the content rights associated with the corresponding media data fileare non-subscription rights or subscription rights. DRM process 1110and/or content playback engine 1120, for example, may access the contentlicense associated with the media data file. If the content rights arenon-subscription rights, personal media device 12 may obtain and/orrender 1162 the media content regardless of the subscription status. DRMprocess 1110 and/or content playback engine 1120, for example, mayretrieve, decrypt and process the media data file associated with theselected non-subscription content item without having to verify devicelicense 424.

If the content rights are subscription rights, personal media device 12may verify 1164 the subscription associated with the personal mediadevice 12. DRM process 1110 on personal media device 12, for example,may access device license 424 to determine if the subscription is validand may compare expiration data 420 to system clock 194 to determine ifthe content has expired. If the subscription cannot be verified (e.g.,the content expired or the subscription is invalid or never existed),personal media device 12 may attempt to renew 1166 an existingsubscription or initiate a new subscription. If the subscription can beverified, personal media device 12 may obtain and/or render 1162 thelicensed media content item. DRM process 1110 and/or content playbackengine 1120 on personal media device 12, for example, may retrieve,decrypt and process the media data file associated with the selectedsubscription content item.

Accordingly, a subscription-based DRM system and method allows a user torender media content under a user subscription on a licensed personalmedia device 12 without having to track content licenses associated witheach media data file individually.

Bulk Licensing Pre-Loaded Media Content:

Referring to FIGS. 18-20, there is shown a system and method for bulklicensing pre-loaded media content on a personal media device 12.Personal media device 12 may be pre-loaded with media content 1200(e.g., on storage device 66 shown in FIG. 3), which may be licensed inbulk, for example, during device initialization. In general, pre-loadedcontent 1200 may be any content that is not downloaded to personal mediadevice 12, for example, from media distribution system 18. Pre-loadedcontent 1200 may be pre-loaded by storing the content when personalmedia device 12 is manufactured, or may be pre-loaded by transferringthe content from another storage medium provided with personal mediadevice 12 (e.g., from a CD or DVD).

As described above, pre-loaded media content 1200 may include media datafiles such as audio files (e.g., music), video files, audio/video files,and multimedia content. Pre-loaded content 1200 may be arranged andpresented as individual media content items (e.g., musical tracks) thatmay be individually and selectively rendered (e.g., subscriptioncontent) and/or as multiple content items that may only be rendered in adefined sequence in compliance with performance complement requirementsand with limited or no user interaction (e.g., non-interactive content).Non-interactive content (also referred to as radio content), forexample, may allow a user to start and stop rendering the sequence ofcontent items and to skip a limited number of content items.

In one example, personal media device 12 may include about 5 to 10gigabytes of pre-loaded content 1200 including content data for about 10to 15 non-interactive content sequences (e.g., radio stations).Pre-loaded content 1200 may correspond to a particular type or categoryof media content to provide a “specialized” personal media device 12.For example, personal media device 12 may be pre-loaded with music of aparticular genre, for example, to provide a Jazz personal media deviceor with music of a particular artist, for example, to provide an Elvispersonal media device.

According to one embodiment, personal media device 12 renders mediacontent if personal media device 12 is initialized and registered orlicensed to a user, for example, under a user subscription to a mediadistribution system. Pre-loaded content 1200 may be pre-loaded beforepersonal media device 12 is initialized and licensed to a user. Incontrast, downloaded content 1202 may be downloaded to personal mediadevice 12, for example, from media distribution system 18, after theuser initializes and licenses the device. Thus, pre-loaded content 1200may advantageously save download bandwidth. The personal media device 12may also enable a limited time trial of pre-loaded content 1200 withouthaving to subscribe to a media distribution system and download content1202.

DRM process 1210 may be resident on and executed by personal mediadevice 12 to perform the core functions and/or processes associated withdigital rights management, for example, as described above. Contentplayback engine 1220 may be resident on and executed by personal mediadevice 12 to perform the core functions or processes associated withrendering media content such as processing media data files. Althoughcontent playback engine 1220 and DRM process 1210 are shown as separatefunctional components, DRM process 1210 may be incorporated with contentplayback engine 1220. DRM process 1210 and content playback engine 1220may be components of device application 64 (FIG. 1), for example, as anembedded feature, software plug-in, or stand-alone application. Theinstruction sets and subroutines of DRM process 1210 and contentplayback engine 1220 may be executed by one or more processors (notshown) and one or more memory architectures (not shown) incorporatedinto personal media device 12.

To prevent media content on personal media device 12 from being accessedor rendered without authorization, media content may be encrypted usingcontent encryption keys (CEKs), as described above. Downloaded content1202 may include embedded content licenses including CEKs 1208, whichmay used to decrypt the downloaded content 1202. Pre-loaded content1200, on the other hand, may be pre-loaded without embedded contentlicenses and CEKs. Thus, the user initially may not render pre-loadedcontent 1200 on personal media device 12 because pre-loaded content 1200is encrypted and the CEKs for decrypting the pre-loaded content 1200 arenot pre-loaded. Content licenses 1204 including CEKs 1208′ correspondingto the pre-loaded content 1210 may be downloaded in bulk, for example,when the personal media device 12 is activated. To bind media content toa subscriber or licensed user of personal media device 12, CEKs 1208,1208′ may be encrypted with user encryption key 422, for example, asdescribed above. User encryption key 422 may then be used by theregistered user or subscriber to decrypt CEKs 1208, 1208′ needed todecrypt media content.

Individual media content items may be identified using content itemidentifiers, such as digital rights management (DRM) IDs used touniquely identify content within media distribution system 18. In oneembodiment, content licenses 1204 may be provided as a sorted or indexeddatabase with content licenses 1204 indexed using content itemidentifiers corresponding to content item identifiers associated withcontent items in pre-loaded content 1200.

An exemplary method of bulk licensing pre-loaded content is illustratedin FIG. 19 and is described below. Personal media device 12 withpre-loaded content 1200 may establish communication with mediadistribution system 18, for example, to register and license personalmedia device 12 during the device initialization process describedabove. When communication is established, media distribution system 18may receive 1250 a request to register and license personal media device12 for use with media distribution system 18. Media distribution system18 may then establish 1252 user encryption key 422 (in addition to otheruser credentials), for example, as described above.

As part of the process of registering and/or licensing personal mediadevice 12, media distribution system 18 may receive 1254 anidentification of pre-loaded content 1200 to be licensed. Personal mediadevice 12, for example, may transmit to media distribution system 18 thecontent item identifiers corresponding to content items in pre-loadedcontent 1200. Media distribution system 18 may then obtain 1256corresponding content licenses for pre-loaded content on personal mediadevice 12. Media distribution system 18, for example, may generate asorted or indexed pre-build database including content licenses 1204(and CEKs 1208′) associated with the content item identifiers providedby personal media device 12. Media distribution system 18 may encryptCEKs 1208′ in the content licenses 1204 with the user encryption key422, for example, in the manner described above for encrypting CEKsembedded in downloaded content. Media distribution system 18 may thentransmit 1260 to personal media device 12 the content licenses 1204 withencrypted CEKs 1208′ for pre-loaded content 1200, which have been boundto user of personal media device 12.

An exemplary method of rendering pre-loaded content is illustrated inFIG. 20 and described below. When a request to render one or more mediacontent items is received 1270, content playback engine 1220 may firstattempt to access 1272 an embedded license, for example, in the headerof the requested media data file. If the requested media data fileincludes an embedded license, a CEK in the embedded license may bedecrypted 1274 with user encryption key 422. If the requested media datafile does not include an embedded license, personal media device 12 maylocate 1276 the CEK associated with the requested media data file anddecrypt 1280 the associated CEK with user encryption key 422. DRMprocess 1210 and/or content playback engine 1220, for example, may usethe content item identifier associated with the requested content itemto locate the content license (and encrypted CEK) in a database ofcontent licenses. Once the corresponding CEK is located and decrypted,the media content item may be decrypted 1282 with the CEK and the mediadata file may be rendered.

Accordingly, the system and method of bulk licensing enables pre-loadedcontent to be securely provided on a personal media device and thenlicensed to a user of the personal media device at a later time in anefficient manner.

Queuing Media Content for Future Purchase:

Referring to FIGS. 21-23, there is shown a system and method for queuingmedia content on personal media device 12 for future purchase from mediadistribution system 18. In general, when personal media device 12 isunable to complete a purchase transaction (e.g., when personal mediadevice 12 is not communicating with media distribution system 18), mediacontent may be queued for future purchase at a subsequent time whenpersonal media device 12 is e.g., communicating with media distributionsystem 18.

Media content that may be queued for future purchase may include anymedia content purchasable from media distribution system 18. Mediacontent may be identified in media distribution system 18 using adigital rights management (DRM) media content identifier. As describedabove, media content that may be purchased may include media data filessuch as audio files (e.g., music), video files, audio/video files, andmultimedia content. Such media content may include subscription content1312 stored on personal media device 12 and non-interactive content 1314stored on personal media device 12. Subscription content 1312 may bearranged and presented as individual media content items that may beindividually and selectively rendered. Non-interactive content 1314 maybe arranged as multiple content items that may only be rendered in adefined sequence in compliance with performance complement requirementsand with limited or no user interaction (e.g., radio content). Bothsubscription content 1312 and non-interactive content 1314 may only berendered for a limited period of time under a valid subscription withmedia distribution system 18. In contrast, purchased media content 1310may be rendered and/or transferred by the user indefinitely andindependent of a subscription status.

Media content items to be purchased may also include media content itemsthat are identified by personal media device 12 (e.g., in a playlist)but are not stored on personal media device 12. Content items to bepurchased may further include content items that are not rendered bypersonal media device 12 (e.g., because there is no valid subscription).

DRM process 1310 may be resident on and executed by personal mediadevice 12 to perform the core functions and/or processes associated withdigital rights management (e.g., as described above). Content playbackengine 1320 may be resident on and executed by personal media device 12to perform the core functions and/or processes associated with renderingmedia content (e.g., processing media data files). Although contentplayback engine 1320 and DRM process 1310 are shown as separatefunctional components, DRM process 1310 may be incorporated with contentplayback engine 1320. DRM process 1310 and content playback engine 1320may be components of device application 64 (FIG. 1) as e.g., an embeddedfeature, a software plug-in, or a stand-alone application. Theinstruction sets and subroutines of DRM process 1310 and contentplayback engine 1320 may be executed by one or more processors (notshown) and one or more memory architectures (not shown) incorporatedinto personal media device 12.

An exemplary method for queuing content items for future purchase isillustrated in FIG. 22 and described below. Personal media device 12 maypresent 1350 identifying information associated with one or more mediacontent items. Personal media device 12 may present such identifyinginformation, for example, when content playback engine 1320 renders theassociated media data file. Alternatively, personal media device 12 maypresent such identifying information e.g., in a content library listingand/or a playlist including the associated media content item.Identifying information associated with the media content items may beobtained from media content metadata (not shown) stored on personalmedia device 12 and/or provided from media distribution system 18.

Personal media device 12 may receive 1354 a purchase request to purchasea media content item presented on personal media device 12. For example,user interface 170 (FIG. 3) may be used to enter the purchase requestwhen the media content item is being rendered on personal media device12. Alternatively, user interface 170 may be used to enter the purchaserequest for a media content item selected from a library listing and/ora playlist.

Upon receiving a purchase request, personal media device 12 maydetermine 1356 whether communication with media distribution system 18is established. If communication is established, personal media device12 and/or media distribution system 18 may execute 1358 a securepurchase transaction to complete the purchase of the selected mediacontent item. A secure purchase transaction may be executed inaccordance with techniques known to those skilled in the art.

If the purchased media content item is currently stored on personalmedia device 12 as either e.g., subscription content 1312 ornon-interactive content 1314, the purchased media content item may thenbe re-licensed 1360 as purchased media content. DRM process 1310 onpersonal media device 12 may e.g., update and/or modify the contentlicense associated with the purchased media content item (e.g., acontent license embedded in the media data file or a content license ina separate content license database) to reflect the new status aspurchased media content. If the purchased media content item is notcurrently stored on personal media device 12 (e.g., as eithersubscription content 1312 or non-interactive content 1314), the mediadata file for the purchased media content item may be downloaded frommedia distribution system 18 to personal media device 12 (e.g., asdescribed above).

If communication is not active (e.g., personal media device 12 is notdocked or communicating via WAP 52, FIG. 1), the content item selectedfor purchase (e.g., via user interface 170) may be identified 1362 inpurchase queue 1316. In an exemplary embodiment, purchase queue 1316 maybe implemented as a purchase queue log file stored on storage device 66(FIG. 1) and DRM content item identifiers corresponding to the contentitems selected for purchase may be defined within the purchase queue logfile. This purchase queue log file may be encrypted and/or authenticatedto provide security for purchase transactions.

An exemplary method for automatically handling purchase transactions forcontent items queued for purchase is illustrated in FIG. 23 and isdescribed below. Personal media device 12 may establish 1370communication with media distribution system 18 after e.g., one or moremedia content items are identified in purchase queue 1316. For example,communication may be established whenever: personal media device 12 isdocked and coupled to proxy computer 54; or personal media device 12 islocated within range of WAP 52.

Upon establishing communication with media distribution system 18,personal media device 12 may transmit 1372 a queue purchase request tomedia distribution system 18 to purchase one or more media content itemsidentified in purchase queue 1316. For example, DRM process 1310 onpersonal media device 12 may encrypt and/or authenticate (e.g.,digitally sign) all or a portion of the above-described purchase queuelog file (e.g., using encryption and/or authentication techniques suchas those described above) to generate the above-described queue purchaserequest.

If the user is authorized 1374 for automatic purchase transactions frommedia distribution system 18, media distribution system 18 may processthe queue purchase request and personal media device 12 may receive 1376confirmation of completed purchase transactions. Authorization forautomatic purchase may be indicated in user subscription data providedby the user (e.g., upon registering and/or modifying a subscription) andmay be stored on personal media device 12 and/or media distributionsystem 18.

If the user is not authorized 1374 for automatic purchase transactionsfrom media distribution system 18, the user may be prompted 1380 toprovide consent 1382. If the user does not manually consent, thepurchase transaction may be aborted 1384. When a purchase transaction iscompleted, the purchased content item may be re-licensed 1378 onpersonal media device 12 as purchased content 1310 (as opposed tosubscription content 1312 or non-interactive content 1314). For example,DRM process 1310 on personal media device 12 may update and/or modify acontent license associated with the purchased content item (e.g., acontent license embedded within the media data file or a content licensein a separate content license database) to reflect the new status aspurchased content.

Accordingly, a user of a personal media device may request purchase ofone or more media content items at any time during use of the personalmedia device, regardless of the communication status with mediadistribution system 18 or the status of the user's subscription.

Automatically Managing Media Content:

Referring to FIGS. 24-26, there is shown a system and method forautomatically managing media content stored on personal media device 12.Media content 1400 may be automatically loaded onto personal mediadevice 12 (e.g., on storage device 66, FIG. 1) and may be automaticallyremoved/released from personal media device 12 to free up storage spacefor new media content to be loaded onto personal media device 12. Mediacontent 1400 may include one or more media content items in the form ofmedia data files (e.g., audio data files, video data files, audio/videodata files, and multimedia data files) renderable on personal mediadevice 12.

Media content 1400 stored on personal media device 12 may include:non-interactive media content 1410 including a plurality of mediacontent items that may be rendered together in a defined sequence withlittle or no user interaction (e.g., radio content); subscription mediacontent 1412 including individual media content items that may beselectively rendered as long as a user has a valid subscription;purchased media content 1414 including individual media content itemspurchased from e.g., media distribution system 18 to be rendered by thepurchasing user without restrictions; and imported media content 1416including media content items imported from another source (e.g., rippedfrom a CD).

As used herein, non-interactive is intended to mean not allowing a userto request a particular media content item for rendering. For example,non-interactive media content 1410 may include a plurality of mediacontent items selected and arranged randomly (or pseudo-randomly) forrendering to a user (e.g., as a radio station). Non-interactive mediacontent playback may allow some level of user control over playback. Forexample, a user may start and stop the playback and/or skip mediacontent items within certain restrictions, as described in greaterdetail in U.S. Provisional Patent Application Ser. No. 60/705,764(Attorney Docket No. REA014), entitled “Systems and Methods forPresenting Media Content”, filed 5 Aug. 2005 and fully incorporatedherein by reference. Non-interactive content may also allow some levelof user input as to the nature of the content. For example, duringnon-interactive music content playback, a user may suggest a musicalartist or a genre of music, which may form the basis for randomly (orpseudo-randomly) selecting media content items for playback.

Non-interactive media content 1410, subscription media content 1412,purchased media content 1414, and imported media content 1416 may beloaded onto personal media device 12 at the request of a user (i.e.,user added media content). Further, non-interactive media content 1410and subscription media content 1412 may also be automatically loadedonto personal media device 12 without being requested by a user (i.e.,automatic media content). Automatic media content may be pre-loaded ontopersonal media device 12 before the user activates/initializes personalmedia device 12 or may be automatically loaded onto personal mediadevice 12 after initialization e.g., based on user preferences, useractivity and user ratings. Information associated with media content1400 (e.g., whether media content was added by a user or addedautomatically) may be stored on personal media device 12 e.g., asmetadata associated with media data files.

Personal media device 12 may also include user data 1440 associated witha user of personal media device 12, such as user playlists 1442, userpreferences 1444, and user metadata 1446. User playlists 1442 mayinclude a list of media content items (e.g., musical tracks) selected bythe user to be rendered in sequence. User preferences 1444 may definethe preferences of a user with respect to media content in general (asopposed to a specific media content item). User preferences 1444 may bebased on user selections and/or recent listening activity and mayinclude favorite genres, favorite artists, and favorite radio stations,for example. User metadata 1446 may include user activity data (e.g.,play count, date added, last played) and user ratings associated withone or more of the media content items stored on personal media device12.

Automatic content loading process 1424 may be resident on and executedby computer 28 and/or proxy computer 54. Automatic content loadingprocess 1424 may associate other media content with media contentpreferred by the user of personal media device 12 and may load theassociated content automatically. Automatic content loading process 1424may be a component of media distribution system 18 or proxy application98 (FIG. 1), for example, as an embedded feature, software plug-in, orstand-alone application. The instruction sets and subroutines ofautomatic content loading process 1424 may be executed by one or moreprocessors (not shown) and one or more memory architectures (not shown)incorporated into computer 28 and/or proxy computer 54.

Automatic content removal process 1430 may be resident on and executedby personal media device 12 to perform the core functions and/orprocesses associated with the automatic removal of content based on therelative weighting of the content. Automatic content removal process1430 may be a component of device application 64 (FIG. 1) as e.g., anembedded feature, a software plug-in, or a stand-alone application. Theinstruction sets and subroutines of automatic content removal process1430 may be executed by one or more processors (not shown) and one ormore memory architectures (not shown) incorporated into personal mediadevice 12.

An exemplary method of automatically adding media content to personalmedia device 12 is illustrated in FIG. 25 and described below. Mediadistribution system 18 may receive 1450 user data 1440′ from personalmedia device 12. User data 1440′ may be provided from personal mediadevice 12 to media distribution system 18 via e.g., proxy computer 54(when personal media device 12 is docked) or WAP 52 (FIG. 1). Mediadistribution system 18 may also include content similarities data 1422defining relationships or associations between various media contentitems. For example, in media distribution system 18, contentsimilarities data 1422 may associate similar musical artists bydefining, for each musical artist, artists who are influences,contemporaries or followers.

Based on user data 1440′ and content similarities data 1422, mediadistribution system 18 may determine 1452 similar content associatedwith content preferred by the user. Automatic content loading process1424 of media distribution system 18 may e.g., retrieve user data 1440′representing content preferred by the user (of personal media device 18)and may derive associations with other content from content similaritiesdata 1422. If user data 1440′ indicates that the user has rated certainmedia content items (e.g., musical tracks) highly, for example,automatic content loading process 1424 may determine (using contentsimilarities data 1422) the artists associated with those highly ratedmedia content items and may retrieve media content items from thoseassociated artists (e.g., influences, contemporaries and followers). Ifuser data 1440′ indicates a favorite artist and/or genre, automaticcontent loading process 1424 may retrieve similar artists from thatgenre using content similarities data 1422.

Similar media content data 1420 may be retrieved 1454 for transmissionto personal media device 12 and may be automatically loaded 1456 ontopersonal media device 12. Once user data 1440′ is sent to mediadistribution system 18, the process of determining and retrievingsimilar content may occur while personal media device 12 is offline(i.e., not in communication with media distribution system 18). Mediadistribution system 18 may communicate with proxy computer 54, forexample, and transmit similar content to proxy computer 54 for loadingonto personal media device 12 during e.g., the next communicationsession.

Media content data 1420 may be automatically loaded as subscriptionmedia content or as non-interactive media content. Non-interactive mediacontent 1410 may be constructed and loaded, for example, on proxycomputer 54. Non-interactive media content 1410 may also be constructedautomatically based on content similarities data 1422.

Media content may be automatically loaded or added to personal mediadevice 12 until personal media device 12 reaches a predetermined storagelimit. The predetermined storage limit may be less than the maximumstorage capacity of personal media device 12, thus allow some additionalstorage space on personal media device 12 for user added media content(or other data). Alternatively, the predetermined storage limit may beset equal to the available space on e.g., storage device 66. If thepredetermined storage limit has been reached, personal media device 12may also attempt to automatically remove media content, as describedbelow.

An exemplary method of automatically removing or releasing media contentfrom personal media device 12 is illustrated in FIG. 26 and describedbelow. When personal media device 12 receives 1480 a request to load newmedia content, personal media device 12 may compare 1482 the size of thenew media content with the storage space remaining on personal mediadevice 12 to determine 1484 if personal media device 12 has sufficientstorage space. As discussed above, this determination may be made bye.g., determining if a predetermined storage limit has been reached ordetermining if there is physically enough storage space available toload the new media content. Media content may be added to personal mediadevice 12 from media distribution system 18, from non-interactive mediacontent 1410, from subscription media content 1412, from purchased mediacontent 1414, from client computer 54 (e.g., as imported media content1416), or from another personal media device (e.g., as “shared”subscription media content 1412), for example.

If personal media device 12 determines 1484 that enough space isavailable, the new media content may be loaded 1492 (e.g., by storingthe content on storage device 66 shown in FIG. 3). If personal mediadevice 12 determines that there is insufficient space for the new mediacontent, personal media device 12 may ascertain (e.g., evaluate and/ordetermine) 1486 the relative weight associated with one or more mediacontent items currently stored on personal media device 12. The relativeweight of a media content item generally corresponds to a likelihoodthat the media content item will be rendered on personal media device 12when compared to the other media content items on personal media device12. Automatic content removal process 1430 on personal media device 12may e.g., evaluate media content items (to determine their relativeweights) by examining user metadata 1446, user preferences 1444 and userplaylists 1442 and may apply a series of algorithms to determine whichmedia content item has a low relative weight.

Concerning the algorithms applied, automatic content removal process1430 may consider e.g., whether a media content item was added by theuser, rated by the user, played by the user, or associated with contentrated or played by the user. In an exemplary embodiment, a media contentitem that was automatically added (e.g., non-interactive content 1410 orsubscription content 1412), that has not been played or rated by theuser, and is not associated with content played or rated by the user maybe weighted lower. On the other hand, a user added media content item(especially, for example, purchased media content 1414 and importedmedia content 1416) may be weighted higher.

Automatic content removal process 1430 may also consider whether a mediacontent item can no longer be rendered on personal media device 12because e.g., the media content item has expired. For example,non-interactive media content 1410 may only be rendered once because ofperformance complement restrictions required by the Digital MillenniumCopyright Act (“DMCA”). Accordingly, non-interactive media content itemsthat have already been rendered may also be weighted lower.

When ascertaining the relative weight of automatic media content thathas been played and/or rated by the user, automatic content removalprocess 1430 may become increasingly complex. If automatic contentremoval process 1430 must choose between automatic media contentassociated with e.g., two different artists, automatic content removalprocess 1430 may look to other factors such as user data 1440. If mediacontent items have been played by a user but not rated, for example,automatic content removal process 1430 may determine which media contentitems have the lower weight by ascertaining which media content itemshave been played less frequently and/or which media content items arenot associated with preferred artists or genres. In one embodiment, useradded media content items may not be automatically removed, although itmay be possible to automatically remove user added content, for example,by looking to user data (e.g., user ratings and preferences).

Automatic content removal process 1430 may automatically delete 1488 oneor more media content items having a comparatively low relative weight.For example, automatic content removal process 1430 (on personal mediadevice 12) may delete media data associated with media content item(s)identified as having a low relative weight. If personal media device 12determines 1490 that sufficient space is still not available, theprocess of ascertaining 1486 relative weights and automatically deleting1488 may be repeated. When sufficient storage space is available, thenew media content items may be loaded 1492.

Accordingly, the system and method for automatically managing mediacontent on personal media device 12 intelligently loads contentappropriate for the user of personal media device 12 and intelligentlyreleases content to make room for new content.

Transferring Media Content Playlists:

Referring to FIGS. 27-29, there is shown a system and method fortransferring media content playlists between personal media devices 12,12′. Playlists 1512 may be shared between personal media devices 12, 12′independent of the architectures, operating systems, and subscriptionstatus of the personal media devices 12, 12′. For example, a playlistgenerated on personal media device 12 that is used in connection with afirst media distribution system (e.g., a media player used with theRhapsody™ service) may be transferred to personal media device 12′ thatis used in connection with a second media distribution system (e.g., aniPod™ player used with the iTunes™ service).

Playlists 1512 may include a list of media content items (e.g., musicaltracks and/or videos) presented to a user for rendering in sequence bye.g., personal media device 12. Media content items may be identified inplaylists 1512 using identifying information associated with the mediacontent items, such as track titles, artist names, various metadata,and/or content item identifiers used by a media distribution system toidentify the media content items. Media content items identified inplaylists 1512 may include media content 1516 (e.g., media data files)stored on personal media device 12 and/or media content (not shown)stored on media distribution system 18. Playlists 1512 may also identifymedia content items stored on neither personal media device 12 nor mediadistribution system 18 (e.g., local media content stored on proxycomputer 54, FIG. 1 or on a different personal media device 12′).

Playlists 1512 may be generated by a user, for example, by selectingeach of the media content items (e.g., tracks) for inclusion in theplaylist or by saving a media history file generated while rendering aseries of media content items. Playlists 1512 may also be generatedautomatically (also referred to as instant playlists) from user datarepresenting a user's listening activities and/or preferences withrespect to media content. User data may include user metadata associatedwith specific media data files (e.g., a user rating, number of timesplayed, last played) and/or general user preferences (e.g., favoriteartist(s) and favorite genre(s)). A playlist compilation system andmethod is described in greater detail in U.S. patent application Ser.No. 11/112,441 (Attorney Docket No. REA002) entitled PLAYLISTCOMPILATION SYSTEM AND METHOD, filed on 22 Apr. 2005, which is fullyincorporated herein by reference.

DRM process 1510 may be resident on and executed by personal mediadevice 12 to perform the core functions and/or processes associated withdigital rights management (e.g., as described above). Content playbackengine 1520 may be resident on and executed by personal media device 12to perform the core functions or processes associated with renderingmedia content (e.g., processing media data files). Although contentplayback engine 1520 and DRM process 1510 are shown as separatefunctional components, DRM process 1510 may be incorporated with contentplayback engine 1520.

Playlist format conversion process 1522 may be resident on and executedby personal media device 12 to perform the core functions and/orprocesses associated with conversion of playlists to a common format fortransmission to another personal media device 12′. Data transfer process1524 may also be resident on and executed by personal media device 12 toperform the core functions and/or processes associated with the transferof data between personal media devices 12, 12′.

DRM process 1510, content playback engine 1520, playlist formatconversion process 1522 and data transfer process 1524 may be componentsof device application 64 (FIG. 1) as e.g., an embedded feature, softwareplug-in, or stand-alone application. The instruction sets andsubroutines of DRM process 1510, content playback engine 1520, playlistformat conversion process 1522, and data transfer process 1524 may beexecuted by one or more processors (not shown) and one or more memoryarchitectures (not shown) incorporated into personal media device 12.

An exemplary method of transferring one or more playlists 1512 betweenpersonal media devices 12, 12′ is illustrated in FIG. 28 and describedbelow. To initiate a playlist transfer from a first personal mediadevice 12 to a second personal media device 12′, a user may select 1550one or more playlists 1512 on personal media device 12. In an exemplaryembodiment, personal media device 12 may display title(s) of playlists1512 on display 90 and slider assembly 88 may be used to scroll throughand select playlists (FIG. 2).

When a transfer is initiated, selected playlists 1512 may be converted1552 into a common format. Alternatively, playlists 1512 may beconverted 1552 into a common format at any time before transferringplaylists 1512 (e.g., before or after the transfer is initiated). In anexemplary embodiment, playlist format conversion process 1522 onpersonal media device 12 may reformat identifying information and/ormetadata (e.g., track titles, artist names, genre, and play time)associated with content items in selected playlists into a common formatusing a standard transport protocol. The common format may be any formatcapable of being processed by different architectures (e.g., an mp3player, a cellular telephone, or a handheld device) and/or operatingsystems (e.g., Microsoft Windows CE™, Redhat Linux™, Palm OS™, or otherdevice-specific operating systems).

To share playlists in the common format (once they are converted 1552),personal media device 12 may establish 1554 communication with anotherpersonal media device 12′ and transfer 1556 one or more playlists 1512in the common format to another personal media device 12′. Data transferprocess 1524 on personal media device 12, for example, may transmitand/or receive the playlist metadata in the common format. Communicationmay be established upon initiation of a playlist transfer or may alreadybe established when the playlist transfer is initiated.

Personal media devices 12, 12′ may communicate directly through awireless communication channel, for example, using IR communicationassembly 186 (FIG. 3) and an infrared data communications protocol knownto those skilled in the art, such as a protocol complying with astandard defined by the Infrared Data Association (IrDA). Personal mediadevices 12, 12′ may also communicate directly through a physicalcoupling such as a wired connection or initiated by physical contactbetween personal media devices 12, 12′ as disclosed in U.S. ProvisionalPatent Application Ser. No. 60/705,747 (Attorney Docket No. REA016),entitled “Personal Media Device”, which was filed on 5 Aug. 2005 and isfully incorporated herein by reference. Alternatively, personal mediadevices 12, 12′ may establish communication indirectly, for example,through proxy computer 54 and/or network(s) 30, 32 (FIG. 1).Transferring playlists between personal media devices 12, 12′ mayaccompany a device-to-device media content transfer but may not requirethe security measures discussed above with respect to device-to-devicemedia content transfers.

An exemplary method of receiving and processing a transferred playlistis illustrated in FIG. 29 and described below. Personal media device 12may receive 1570 a transferred playlist in the common format, which hasbeen transferred from another personal media device 12′. Personal mediadevice 12 may then convert 1572 the playlist in the common format to aplaylist 1512 in a format compatible with personal media device 12. Forexample, playlist format conversion process 1522 on personal mediadevice 12 may re-format the identifying information and/or metadataassociated with each of the media content items in the transferredplaylist into a format that is recognizable and processable by personalmedia device 12. Playlist format conversion process 1522 may also addmetadata, such as media content item identifiers, used by the mediadistribution system for which personal media device 12 is registered.For example, if a playlist generated in connection with the iTunes™service is converted to a playlist for use in connection with theRhapsody™ service, media content item identifiers unique to theRhapsody™ service may be added to the metadata in the playlist.

After converting the transferred playlist metadata, a user may initiateplayback of the transferred playlists 1512. Accordingly, personal mediadevice 12 may receive 1574 a request to obtain and/or render mediacontent identified in the transferred playlist. The user may initiateplayback, on personal media device 12, of all of playlist 1512, aportion of playlist 1512, or a single media content item within playlist1512. Playback may be initiated, for example, by selecting the playlistor media content item on display panel 90 (FIG. 2) and actuatingplay/pause switch 82 (FIG. 2). Upon receiving a request to obtain and/orrender media content items in the transferred playlist, content playbackengine 1520 on personal media device 12 may attempt 1575 to retrieve andrender media data file(s) for the selected media content item(s).

Before content playback engine 1520 renders media content itemsidentified in a transferred playlist, content playback engine 1520 maydetermine if the media data files are available 1576 (e.g., stored onpersonal media device 12). If a media data file is not available,content playback engine 1520 may attempt to retrieve 1575 another mediadata file for another content item identified in the transferredplaylist. Alternatively, if media data files are not available onpersonal media device 12, personal media device 12 may attempt to obtainthe unavailable media data files by e.g., establishing communicationwith media distribution system 18 (as described above). Personal mediadevice 12 may also attempt to obtain media data files by establishingcommunication with proxy computer 54 (FIG. 1) and/or by initiating adevice-to-device media content transfer with another personal mediadevice 12′ (e.g., as described above).

Before content playback engine 1520 renders media content itemsidentified in the transferred playlist, content playback engine 1520 mayalso determine if personal media device 12 and/or the user hasappropriate content rights to render each media content item. DRMprocess 1510 and/or content playback engine 1520, for example, mayaccess content licenses associated with the media data files selectedfor playback to determine the content rights associated with the mediadata files. If the content rights indicate non-subscription rights 1582(e.g., the content item has been purchased or imported), for example,content playback engine 1520 may retrieve and render 1584 the media datafile without verifying a subscription.

If the content rights indicate subscription rights, personal mediadevice 12 may attempt to verify 1586 a device license to determine ifpersonal media device 12 has valid subscription rights for the mediacontent item to be rendered. DRM process 1510, for example, may verifythe device license and determine if a timeout has expired (e.g., asdescribed above). If subscription rights are not available and/or cannotbe verified, DRM process 1510 may attempt 1588 to subscribe and/or renewa subscription (e.g., as described above). If subscription rights areverified, content playback engine 1520 may retrieve and render the mediadata file. This process may be repeated for each media content item tobe rendered in the transferred playlist.

Accordingly, the system and method enables playlists to be sharedbetween personal media devices 12, 12′ independent of devicearchitectures, operating systems, and subscriptions.

Exchanging and Dynamically Updating User Profiles:

Referring to FIGS. 30-32, there is shown a system and method forexchanging user profiles between personal media devices 12, 12′ anddynamically updating the exchanged user profiles. User profiles may beexchanged to and from personal media device 12 and then dynamicallyupdated when personal media device 12 establishes communication withmedia distribution system 18. User profile 1610 may be stored onpersonal media device 12 (e.g., on storage device 66) and may include atleast a user ID capable of identifying a user within media distributionsystem 18. User profile 1610 may also include other informationassociated with the user such as a user name, age, gender, contactinformation (e.g., email address, telephone number, instant messengeraddress) and other information associated with the user's media contentactivity and preferences.

Data transfer process 1620 may be resident on and executed by personalmedia device 12 and may perform the core functions and/or processesassociated with data transfer between personal media device 12 and asecond personal media device 12′. Data transfer process 1620 may be acomponent of device application 64 (FIG. 1), for example, as an embeddedfeature, software plug-in, or a stand-alone application.

Dynamic updating process 1622 may be resident on and executed bypersonal media device 12, proxy computer 54 (FIG. 1) or server computer28 (FIG. 1) and may update user profiles in user profile database 1618.Dynamic updating process 1622 may be a component of device application64 (FIG. 1), proxy application 98 (FIG. 1) or media distribution system18, for example, as an embedded feature, software plug-in, orstand-alone application. The instruction sets and subroutines of datatransfer process 1620 and dynamic updating process 1622 may be executedby one or more processors (not shown) and one or more memoryarchitectures (not shown) incorporated into personal media device 12,proxy computer 54 and/or server computer 28.

An exemplary method of exchanging user profiles between personal mediadevices 12, 12′ is illustrated in FIG. 31 and described below. Personalmedia device 12 may generate 1650 user profile 1610 associated with theregistered user of personal media device 12. Typically, personal mediadevice 12 has only one registered user, although multiple registeredusers and user profiles are possible. User profile 1610 may begenerated, for example, during the device initialization processdescribed above, and/or when media distribution system 18 establishes aunique user ID to identify the registered user of personal media device12 with media distribution system 18. A user may also be prompted toenter any additional information to be included within user profile1610. A user may also configure personal media device 12 by enteringconfiguration settings that define the level or degree of sharing thatis authorized for user profile 1610. For example, the user may authorizesharing of only a user ID without any other personal information. Theuser may also authorize sharing of user profile 1610 automatically withany other personal media device (e.g., second personal media device 12′)without any user action. Alternatively, the user may authorize sharingof user profile 1610 only when initiated by the user or only to certainother personal media devices (e.g., devices with matching media contentpersonas, as described below). Further, the user may configure personalmedia device 12 to disable sharing entirely.

Before transferring data, personal media device 12 may establish 1652communication with second personal media device 12′. Personal mediadevices 12, 12′ may communicate directly through a wirelesscommunication channel, for example, using IR communication assembly 186(FIG. 3) and an infrared data communications protocol known to thoseskilled in the art, such as a protocol complying with a standard definedby the Infrared Data Association (IrDA). Personal media devices 12, 12′may also communicate directly through a physical coupling such as ahard-wired connection. Communication may be initiated by physicalcontact between personal media devices 12, 12′ as disclosed in U.S.Provisional Patent Application Ser. No. 60/705,747 (Attorney Docket No.REA016), entitled “Personal Media Device and Methods of Using Same”,which was filed on 5 Aug. 2005 and is fully incorporated herein byreference. Alternatively, personal media devices 12, 12′ may establishcommunication indirectly, for example, through proxy computer 54(FIG. 1) and/or network(s) 30, 32 (FIG. 1).

Once communication has been established, one or both personal mediadevices 12, 12′ may initiate 1654 a user profile exchange or transfer. Auser profile exchange may occur when personal media devices 12, 12′ aresharing other data e.g., a device-to-device media content transfer or aplaylist transfer. Alternatively, a user profile exchange may occurindependently (i.e., without transferring or sharing other data).

When a profile exchange or transfer is initiated by second personalmedia device 12′, personal media device 12 may confirm 1656 thatpersonal media device 12 is authorized to share profile 1610 (e.g., bychecking user configuration settings and prompting the user ifnecessary). If authorized to share profile 1610, personal media device12 may transmit 1660 user profile 1610 to personal media device 12′and/or may receive 1662 a user profile (e.g., a friend's user profile)from another personal media device (e.g., second personal media device12′).

Data transfer process 1620 on personal media device 12 may transmitand/or receive user profiles. User profiles received from other personalmedia devices may be stored by personal media device 12 as e.g., friendprofile(s) 1612. As mentioned above, each friend profile 1612 mayinclude at least a user ID associated with the user of the otherpersonal media device. In one embodiment, user profiles exchangedbetween personal media devices 12, 12′ may include only a user ID, andother user profile data may be obtained by establishing communicationwith media distribution system 18 (to be discussed below in greaterdetail).

An exemplary method of dynamically updating profiles is illustrated inFIG. 32 and is described below. Personal media device 12 may establish1670 communication with media distribution system 18 (e.g., via proxycomputer 54 or via a WAP 52). Media distribution system 18 may includeuser profile database 1618 that includes user profiles for registeredusers/subscribers of media distribution system 18. User profile database1618 may include, in addition to user IDs, additional informationassociated with the user's media content activity and preferences. In anexemplary embodiment of media distribution system 18, user profiles maydefine playlists generated by the user, music genres selected by theuser, artists selected by the user, and recent listening activities(e.g., tracks and/or artists) of the user.

Upon establishing communication with media distribution system 18;personal media device 12, media distribution system 18 and/or proxycomputer 54 may determine if user profile 1610 in user profile database1618 is up-to-date. This determination may be made by comparing theversion of user profile 1610 stored within database 1618 to the versionof user profile 1610 stored on personal media device 12. If the versionof user profile 1610 stored within database 1618 needs to be updated,dynamic updating process 1622 may update 1672 database 1618 by uploading1674 all or a portion of the version of user profile 1610 stored onpersonal media device 12 to user profile database 1618. Accordingly,dynamic updating process 1622 may synchronize the version of userprofile 1610 stored on personal media device 12 and the version of userprofile 1610 stored within database 1618. As discussed above, userprofiles may define e.g., a user ID, a user name, age, gender, contactinformation (e.g., email address, telephone number, instant messengeraddress), playlists generated by the user, music genres selected by theuser, artists selected by the user, and recent listening activities(e.g., tracks and/or artists) of the user, for example.

Upon establishing communication with media distribution system 18;personal media device 12, media distribution system 18 and/or proxycomputer 54 may also determine if friend profile 1612 is up-to-date.This determination may be made by comparing the version of friendprofile 1612 stored within database 1618 to the version of the friendprofile 1612 stored on personal media device 12. If the version offriend profile 1612 stored on personal media device 12 needs to beupdated, dynamic updating process 1622 may update 1676 personal mediadevice 12 by downloading 1680 all or a portion of the version of friendprofile 1612 stored within database 1618 to personal media device 12.Additionally/alternatively, the up-to-date friend profile may bepresented to the user as e.g., a web page and may be accessed usingpersonal media device 12 or proxy computer 54 (FIG. 1), for example

When a friend profile 1612 on personal media device 12 includes only auser ID, the user ID in friend profile 1612 may provide a link to a morecomplete friend profile in user profile database 1618, which may bedownloaded to personal media device 12 (as described above) or presentedto the user as e.g., a webpage (as described above).

The user of personal media device 12 may continue to obtain updatedinformation associated with friend profile 1612 that was transferredfrom another personal media device (e.g., second personal media device12′) to user profile database 1618. Once completed, the profile updatingprocess may be stopped 1682.

Accordingly, a system and method for exchanging and dynamically updatingprofiles allows users of personal media devices 12, 12′ to establishrelationships.

Comparing User Media Personas:

Referring to FIGS. 33 and 34, there is shown a system and method forcomparing user media personas on personal media devices 12, 12′. Thesystem and method may compare user media personas associated with usersof personal media devices 12, 12′ within proximity of each other todetermine if the users have similar interests or patterns in mediacontent (e.g., similar music interests or patterns).

User profile 1710 may be stored on personal media device 12 and mayinclude at least a user ID capable of identifying a user within mediadistribution system 18 (e.g., as described above). User profile 1710 mayalso include other information associated with a user such as a username, age, gender, contact information (e.g., email address, telephonenumber, instant messenger address). User persona 1712 may also be storedon personal media device 12 and may include other information associatedwith the user's media content activity and preferences. For example, fora music distribution system, a user persona may include datarepresenting the music that the user has listened to, the type of musicplaylists the user has generated, and the type of artists and/or genresthe user prefers.

Data transfer process 1720 may be resident on and executed by personalmedia device 12 and may perform the core functions and/or processesassociated with the transfer of data to and from personal media devices12, 12′. Persona generation process 1730 may be resident on and executedby personal media device 12 to generate a user persona based on userpreferences and user activities.

Pattern matching process 1732 may be resident on and executed bypersonal media device 12 to match multiple personas to determinesimilarities in user preferences and user activities. Data transferprocess 1720, persona generation process 1730 and pattern matchingprocess 1732 may be components of device application 64 (FIG. 1), forexample, as an embedded feature, a software plug-in, or a stand-aloneapplication. The instruction sets and subroutines of data transferprocess 1720, persona generation process 1730, and pattern matchingprocess 1732 may be executed by one or more processors (not shown) andone or more memory architectures (not shown) incorporated into personalmedia device 12.

An exemplary embodiment of exchanging and comparing user media personasis illustrated in FIG. 34 and is described below. Personal media device12 may generate 1750 user media persona 1712 from user data 1740 storedon personal media device 12. Persona generation process 1730 on personalmedia device 12, for example, may compile data representing user mediapersona 1712 from user playlists 1742 generated by the user, generaluser preferences 1744 entered by the user (e.g., favorite genres andartists), and user metadata 1744 associated with specific content items(e.g., user ratings, number of times played, last played). User mediapersona 1712 may include, for example, data identifying tracks that havebeen highly rated, listened to frequently, listened to recently, and/oradded to playlists; data identifying favorite artists; and dataidentifying favorite genres. Persona generation process 1730 may thenstore the data representing user media persona 1712 as a file or datastructure on personal media device 12.

Personal media devices 12, 12′ may establish 1752 communication, forexample, using a wireless protocol. Personal media devices 12, 12′ mayinitiate wireless communication with other personal media devices withinthe wireless communication range of personal media devices 12, 12′(e.g., in a round robin fashion). Alternatively, personal media devices12, 12′ may establish communication using an IR data communicationsprotocol or using a physical coupling (e.g., a cable), as describedabove. Communication may be established as part of another data transfer(e.g., a device-to-device transfer, a user profile transfer, or playlisttransfer).

Once communication is established, one personal media device 12 mayreceive 1754 a user media persona transferred by the data transferprocess 1720 of another personal media device 12′. For example, personalmedia device 12 may receive the user media persona for the user ofpersonal media device 12′. In particular, personal media device 12′ mayact as a master device and push a user media persona (defining thelikes/interests of the user of personal media device 12′) to personalmedia device 12 (which acts as a slave device). A user may configurepersonal media device 12 to transmit/receive media personas only to/fromcertain other users or to disable the process of transmitting and/orreceiving media personas from other personal media devices.

Personal media device 12 (i.e., the slave device) may then compare 1756the received user media persona (which defines the likes/interests ofthe user of personal media device 12′) with user media persona 1712(which defines the likes/interests of the user of personal media device12). Pattern matching process 1732 on personal media device 12, forexample, may compare the data included within the user media personas todetermine 1758 if there is any matching data (e.g., artists, genres,tracks) between the two personas. A user may configure pattern matchingprocess 1732 to define what constitutes matching data. The matchingdegree may be set, for example, to require an exact match of all usermedia persona data (e.g., all artists, genres, and tracks), a match ofmost user media persona data (e.g., 51% of all artists, genres, andtracks), or a match of any user media persona data (e.g., any artist,genre, or track).

Upon determining a matching pattern, personal media device 12 (i.e., theslave device) may generate 1760 a matching persona notificationnotifying the user of personal media device 12 (i.e., the slave device)and/or the user of personal media device 12′ (i.e., the master device)that a user with similar interests and patterns has been located.

The notification may provide additional information such as the physicaldistance of the other personal media device having the matching personaand/or a summary of the matching data. Upon notification of a match,personal media devices 12, 12′ may also exchange personal informationsuch as a name and contact information (e.g., email address, instantmessenger address, and/or telephone number) to allow the users tocommunicate. Personal media devices 12, 12′ may also exchange userprofiles 1710 (e.g., as described above). Personal information and/oruser profile 1710 may be transmitted automatically upon receivingnotification of matching user persona data, or may be transmitted inresponse to the authorization of the user. The user may also configurepersonal media device 12 to suppress the transmission of personalinformation and/or user profiles. Upon notification of a match, users ofpersonal media devices 12, 12′ may also initiate a device-to-devicemedia content transfer, as described above.

Accordingly, a system and method of comparing user media personas mayallow a user to identify and locate other users with similar mediacontent interests and patterns (e.g., similar music interests andlistening patterns).

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made. Accordingly, otherimplementations are within the scope of the following claims.

1. A method comprising: selecting at least one playlist for transfer,the at least one playlist being stored on a first personal media device;converting the at least one playlist to a common format, thus generatinga first common format playlist; establishing communication with a secondpersonal media device; and transferring the first common format playlistto the second personal media device.
 2. The method of claim 1 furthercomprising: receiving a second common format playlist on the firstpersonal media device.
 3. The method of claim 2 further comprising:converting the second common format playlist into a format useable bythe first personal media device, thus generating a reformated playlist.4. The method of claim 3 further comprising: rendering, on the firstpersonal media device, one or more media data files associated with oneor more media content items defined in the reformated playlist.
 5. Themethod of claim 4 further comprising: downloading, from a mediadistribution system, the one or more media data files associated withthe one or more media content items defined in the reformated playlist.6. The method of claim 4 further comprising: determining if the firstpersonal media device has sufficient subscription rights for renderingthe one or more media data files associated with the one or more mediacontent items defined in the reformated playlist.
 7. A computer programproduct residing on a computer readable medium having a plurality ofinstructions stored thereon that, when executed by a processor, causethe processor to perform operations comprising: selecting at least oneplaylist for transfer, the at least one playlist being stored on a firstpersonal media device; converting the at least one playlist to a commonformat, thus generating a first common format playlist; establishingcommunication with a second personal media device; and transferring thefirst common format playlist to the second personal media device.
 8. Thecomputer program product of claim 7 further comprising instructions forperforming operations comprising: receiving a second common formatplaylist on the first personal media device.
 9. The computer programproduct of claim 8 further comprising instructions for performingoperations comprising: converting the second common format playlist intoa format useable by the first personal media device, thus generating areformated playist.
 10. The computer program product of claim 9 furthercomprising instructions for performing operations comprising: rendering,on the first personal media device, one or more media data filesassociated with one or more media content items defined in thereformated playlist.
 11. The computer program product of claim 10further comprising instructions for performing operations comprising:downloading, from a media distribution system, the one or more mediadata files associated with the one or more media content items definedin the reformated playlist.
 12. The computer program product of claim 10further comprising instructions for performing operations comprising:determining if the first personal media device has sufficientsubscription rights for rendering the one or more media data filesassociated with the one or more media content items defined in thereformated playlist.
 13. A computing device configured to performoperations comprising: selecting at least one playlist for transfer, theat least one playlist being stored on a first personal media device;converting the at least one playlist to a common format, thus generatinga first common format playlist; establishing communication with a secondpersonal media device; and transferring the first common format playlistto the second personal media device.
 14. The computing device of claim13, wherein the computing device is further configured to performoperations comprising: receiving a second common format playlist on thefirst personal media device.
 15. The computing device of claim 14,wherein the computing device is further configured to perform operationscomprising: converting the second common format playlist into a formatuseable by the first personal media device, thus generating a reformatedplayist.
 16. The computing device of claim 15, wherein the computingdevice is further configured to perform operations comprising:rendering, on the first personal media device, one or more media datafiles associated with one or more media content items defined in thereformated playlist.
 17. The computing device of claim 16, wherein thecomputing device is further configured to perform operations comprising:downloading, from a media distribution system, the one or more mediadata files associated with the one or more media content items definedin the reformated playlist.
 18. The computing device of claim 16,wherein the computing device is further configured to perform operationscomprising: determining if the first personal media device hassufficient subscription rights for rendering the one or more media datafiles associated with the one or more media content items defined in thereformated playlist.